diff --git a/src/AsyncWrapper.tsx b/src/AsyncWrapper.tsx
index 179d42668e..cec814df17 100644
--- a/src/AsyncWrapper.tsx
+++ b/src/AsyncWrapper.tsx
@@ -37,6 +37,7 @@ export default class AsyncWrapper extends React.Component<IProps, IState> {
     public state: IState = {};
 
     public componentDidMount(): void {
+        this.unmounted = false;
         this.props.prom
             .then((result) => {
                 if (this.unmounted) return;
diff --git a/src/async-components/views/dialogs/security/CreateSecretStorageDialog.tsx b/src/async-components/views/dialogs/security/CreateSecretStorageDialog.tsx
index 3022aa6b8d..1e87b5b826 100644
--- a/src/async-components/views/dialogs/security/CreateSecretStorageDialog.tsx
+++ b/src/async-components/views/dialogs/security/CreateSecretStorageDialog.tsx
@@ -117,8 +117,6 @@ export default class CreateSecretStorageDialog extends React.PureComponent<IProp
             // signing key upload as well. This avoids hitting the server to
             // test auth flows, which may be slow under high load.
             canUploadKeysWithPasswordOnly = true;
-        } else {
-            this.queryKeyUploadAuth();
         }
 
         const keyFromCustomisations = ModuleRunner.instance.extensions.cryptoSetup.createSecretStorageKey();
@@ -140,8 +138,15 @@ export default class CreateSecretStorageDialog extends React.PureComponent<IProp
             passPhraseKeySelected,
             accountPassword,
         };
+    }
 
+    public componentDidMount(): void {
+        const keyFromCustomisations = ModuleRunner.instance.extensions.cryptoSetup.createSecretStorageKey();
         if (keyFromCustomisations) this.initExtension(keyFromCustomisations);
+
+        if (this.state.canUploadKeysWithPasswordOnly === null) {
+            this.queryKeyUploadAuth();
+        }
     }
 
     private initExtension(keyFromCustomisations: Uint8Array): void {
diff --git a/src/async-components/views/dialogs/security/ExportE2eKeysDialog.tsx b/src/async-components/views/dialogs/security/ExportE2eKeysDialog.tsx
index 3913d7a806..673ff5e399 100644
--- a/src/async-components/views/dialogs/security/ExportE2eKeysDialog.tsx
+++ b/src/async-components/views/dialogs/security/ExportE2eKeysDialog.tsx
@@ -56,6 +56,10 @@ export default class ExportE2eKeysDialog extends React.Component<IProps, IState>
         };
     }
 
+    public componentDidMount(): void {
+        this.unmounted = false;
+    }
+
     public componentWillUnmount(): void {
         this.unmounted = true;
     }
diff --git a/src/async-components/views/dialogs/security/ImportE2eKeysDialog.tsx b/src/async-components/views/dialogs/security/ImportE2eKeysDialog.tsx
index fa41d53a45..d08259f2cb 100644
--- a/src/async-components/views/dialogs/security/ImportE2eKeysDialog.tsx
+++ b/src/async-components/views/dialogs/security/ImportE2eKeysDialog.tsx
@@ -64,6 +64,10 @@ export default class ImportE2eKeysDialog extends React.Component<IProps, IState>
         };
     }
 
+    public componentDidMount(): void {
+        this.unmounted = false;
+    }
+
     public componentWillUnmount(): void {
         this.unmounted = true;
     }
diff --git a/src/components/structures/InteractiveAuth.tsx b/src/components/structures/InteractiveAuth.tsx
index 91e52a1905..4b0f060952 100644
--- a/src/components/structures/InteractiveAuth.tsx
+++ b/src/components/structures/InteractiveAuth.tsx
@@ -90,8 +90,8 @@ interface IState {
 
 export default class InteractiveAuthComponent<T> extends React.Component<InteractiveAuthProps<T>, IState> {
     private readonly authLogic: InteractiveAuth<T>;
-    private readonly intervalId: number | null = null;
     private readonly stageComponent = createRef<IStageComponent>();
+    private intervalId: number | null = null;
 
     private unmounted = false;
 
@@ -126,15 +126,17 @@ export default class InteractiveAuthComponent<T> extends React.Component<Interac
                 AuthType.SsoUnstable,
             ],
         });
+    }
+
+    public componentDidMount(): void {
+        this.unmounted = false;
 
         if (this.props.poll) {
             this.intervalId = window.setInterval(() => {
                 this.authLogic.poll();
             }, 2000);
         }
-    }
 
-    public componentDidMount(): void {
         this.authLogic
             .attemptAuth()
             .then(async (result) => {
diff --git a/src/components/structures/LeftPanel.tsx b/src/components/structures/LeftPanel.tsx
index f8cd0184d4..49d0f570a5 100644
--- a/src/components/structures/LeftPanel.tsx
+++ b/src/components/structures/LeftPanel.tsx
@@ -67,10 +67,6 @@ export default class LeftPanel extends React.Component<IProps, IState> {
             activeSpace: SpaceStore.instance.activeSpace,
             showBreadcrumbs: LeftPanel.breadcrumbsMode,
         };
-
-        BreadcrumbsStore.instance.on(UPDATE_EVENT, this.onBreadcrumbsUpdate);
-        RoomListStore.instance.on(LISTS_UPDATE_EVENT, this.onBreadcrumbsUpdate);
-        SpaceStore.instance.on(UPDATE_SELECTED_SPACE, this.updateActiveSpace);
     }
 
     private static get breadcrumbsMode(): BreadcrumbsMode {
@@ -78,6 +74,10 @@ export default class LeftPanel extends React.Component<IProps, IState> {
     }
 
     public componentDidMount(): void {
+        BreadcrumbsStore.instance.on(UPDATE_EVENT, this.onBreadcrumbsUpdate);
+        RoomListStore.instance.on(LISTS_UPDATE_EVENT, this.onBreadcrumbsUpdate);
+        SpaceStore.instance.on(UPDATE_SELECTED_SPACE, this.updateActiveSpace);
+
         if (this.listContainerRef.current) {
             UIStore.instance.trackElementDimensions("ListContainer", this.listContainerRef.current);
             // Using the passive option to not block the main thread
diff --git a/src/components/structures/MatrixChat.tsx b/src/components/structures/MatrixChat.tsx
index d0edcccd4f..80a648b5d5 100644
--- a/src/components/structures/MatrixChat.tsx
+++ b/src/components/structures/MatrixChat.tsx
@@ -231,10 +231,10 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
     private prevWindowWidth: number;
     private voiceBroadcastResumer?: VoiceBroadcastResumer;
 
-    private readonly loggedInView: React.RefObject<LoggedInViewType>;
-    private readonly dispatcherRef: string;
-    private readonly themeWatcher: ThemeWatcher;
-    private readonly fontWatcher: FontWatcher;
+    private readonly loggedInView = createRef<LoggedInViewType>();
+    private dispatcherRef?: string;
+    private themeWatcher?: ThemeWatcher;
+    private fontWatcher?: FontWatcher;
     private readonly stores: SdkContextClass;
 
     public constructor(props: IProps) {
@@ -256,8 +256,6 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
             ready: false,
         };
 
-        this.loggedInView = createRef();
-
         SdkConfig.put(this.props.config);
 
         // Used by _viewRoom before getting state from sync
@@ -282,32 +280,10 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
         }
 
         this.prevWindowWidth = UIStore.instance.windowWidth || 1000;
-        UIStore.instance.on(UI_EVENTS.Resize, this.handleResize);
-
-        // For PersistentElement
-        this.state.resizeNotifier.on("middlePanelResized", this.dispatchTimelineResize);
-
-        RoomNotificationStateStore.instance.on(UPDATE_STATUS_INDICATOR, this.onUpdateStatusIndicator);
-
-        this.dispatcherRef = dis.register(this.onAction);
-
-        this.themeWatcher = new ThemeWatcher();
-        this.fontWatcher = new FontWatcher();
-        this.themeWatcher.start();
-        this.fontWatcher.start();
 
         // object field used for tracking the status info appended to the title tag.
         // we don't do it as react state as i'm scared about triggering needless react refreshes.
         this.subTitleStatus = "";
-
-        initSentry(SdkConfig.get("sentry"));
-
-        if (!checkSessionLockFree()) {
-            // another instance holds the lock; confirm its theft before proceeding
-            setTimeout(() => this.setState({ view: Views.CONFIRM_LOCK_THEFT }), 0);
-        } else {
-            this.startInitSession();
-        }
     }
 
     /**
@@ -476,6 +452,29 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
     }
 
     public componentDidMount(): void {
+        UIStore.instance.on(UI_EVENTS.Resize, this.handleResize);
+
+        // For PersistentElement
+        this.state.resizeNotifier.on("middlePanelResized", this.dispatchTimelineResize);
+
+        RoomNotificationStateStore.instance.on(UPDATE_STATUS_INDICATOR, this.onUpdateStatusIndicator);
+
+        this.dispatcherRef = dis.register(this.onAction);
+
+        this.themeWatcher = new ThemeWatcher();
+        this.fontWatcher = new FontWatcher();
+        this.themeWatcher.start();
+        this.fontWatcher.start();
+
+        initSentry(SdkConfig.get("sentry"));
+
+        if (!checkSessionLockFree()) {
+            // another instance holds the lock; confirm its theft before proceeding
+            setTimeout(() => this.setState({ view: Views.CONFIRM_LOCK_THEFT }), 0);
+        } else {
+            this.startInitSession();
+        }
+
         window.addEventListener("resize", this.onWindowResized);
     }
 
@@ -497,8 +496,8 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
     public componentWillUnmount(): void {
         Lifecycle.stopMatrixClient();
         dis.unregister(this.dispatcherRef);
-        this.themeWatcher.stop();
-        this.fontWatcher.stop();
+        this.themeWatcher?.stop();
+        this.fontWatcher?.stop();
         UIStore.destroy();
         this.state.resizeNotifier.removeListener("middlePanelResized", this.dispatchTimelineResize);
         window.removeEventListener("resize", this.onWindowResized);
@@ -1011,7 +1010,7 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
 
         this.setStateForNewView(newState);
         ThemeController.isLogin = true;
-        this.themeWatcher.recheck();
+        this.themeWatcher?.recheck();
         this.notifyNewScreen(isMobileRegistration ? "mobile_register" : "register");
     }
 
@@ -1088,7 +1087,7 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
             },
             () => {
                 ThemeController.isLogin = false;
-                this.themeWatcher.recheck();
+                this.themeWatcher?.recheck();
                 this.notifyNewScreen("room/" + presentedId, replaceLast);
             },
         );
@@ -1113,7 +1112,7 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
         });
         this.notifyNewScreen("welcome");
         ThemeController.isLogin = true;
-        this.themeWatcher.recheck();
+        this.themeWatcher?.recheck();
     }
 
     private viewLogin(otherState?: any): void {
@@ -1123,7 +1122,7 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
         });
         this.notifyNewScreen("login");
         ThemeController.isLogin = true;
-        this.themeWatcher.recheck();
+        this.themeWatcher?.recheck();
     }
 
     private viewHome(justRegistered = false): void {
@@ -1136,7 +1135,7 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
         this.setPage(PageType.HomePage);
         this.notifyNewScreen("home");
         ThemeController.isLogin = false;
-        this.themeWatcher.recheck();
+        this.themeWatcher?.recheck();
     }
 
     private viewUser(userId: string, subAction: string): void {
@@ -1357,7 +1356,7 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
      */
     private async onLoggedIn(): Promise<void> {
         ThemeController.isLogin = false;
-        this.themeWatcher.recheck();
+        this.themeWatcher?.recheck();
         StorageManager.tryPersistStorage();
 
         await this.onShowPostLoginScreen();
diff --git a/src/components/structures/MessagePanel.tsx b/src/components/structures/MessagePanel.tsx
index 7383e06f07..b26de2e645 100644
--- a/src/components/structures/MessagePanel.tsx
+++ b/src/components/structures/MessagePanel.tsx
@@ -240,13 +240,13 @@ export default class MessagePanel extends React.Component<IProps, IState> {
     private readReceiptsByUserId: Map<string, IReadReceiptForUser> = new Map();
 
     private readonly _showHiddenEvents: boolean;
-    private isMounted = false;
+    private unmounted = false;
 
     private readMarkerNode = createRef<HTMLLIElement>();
     private whoIsTyping = createRef<WhoIsTypingTile>();
     public scrollPanel = createRef<ScrollPanel>();
 
-    private readonly showTypingNotificationsWatcherRef: string;
+    private showTypingNotificationsWatcherRef?: string;
     private eventTiles: Record<string, UnwrappedEventTile> = {};
 
     // A map to allow groupers to maintain consistent keys even if their first event is uprooted due to back-pagination.
@@ -267,22 +267,21 @@ export default class MessagePanel extends React.Component<IProps, IState> {
         // and we check this in a hot code path. This is also cached in our
         // RoomContext, however we still need a fallback for roomless MessagePanels.
         this._showHiddenEvents = SettingsStore.getValue("showHiddenEventsInTimeline");
+    }
 
+    public componentDidMount(): void {
+        this.unmounted = false;
         this.showTypingNotificationsWatcherRef = SettingsStore.watchSetting(
             "showTypingNotifications",
             null,
             this.onShowTypingNotificationsChange,
         );
-    }
-
-    public componentDidMount(): void {
         this.calculateRoomMembersCount();
         this.props.room?.currentState.on(RoomStateEvent.Update, this.calculateRoomMembersCount);
-        this.isMounted = true;
     }
 
     public componentWillUnmount(): void {
-        this.isMounted = false;
+        this.unmounted = true;
         this.props.room?.currentState.off(RoomStateEvent.Update, this.calculateRoomMembersCount);
         SettingsStore.unwatchSetting(this.showTypingNotificationsWatcherRef);
         this.readReceiptMap = {};
@@ -441,7 +440,7 @@ export default class MessagePanel extends React.Component<IProps, IState> {
     }
 
     private isUnmounting = (): boolean => {
-        return !this.isMounted;
+        return this.unmounted;
     };
 
     public get showHiddenEvents(): boolean {
diff --git a/src/components/structures/NonUrgentToastContainer.tsx b/src/components/structures/NonUrgentToastContainer.tsx
index 2eca6db934..d01bf78959 100644
--- a/src/components/structures/NonUrgentToastContainer.tsx
+++ b/src/components/structures/NonUrgentToastContainer.tsx
@@ -25,7 +25,9 @@ export default class NonUrgentToastContainer extends React.PureComponent<IProps,
         this.state = {
             toasts: NonUrgentToastStore.instance.components,
         };
+    }
 
+    public componentDidMount(): void {
         NonUrgentToastStore.instance.on(UPDATE_EVENT, this.onUpdateToasts);
     }
 
diff --git a/src/components/structures/RoomSearch.tsx b/src/components/structures/RoomSearch.tsx
index 26df4d3e08..35751ef35f 100644
--- a/src/components/structures/RoomSearch.tsx
+++ b/src/components/structures/RoomSearch.tsx
@@ -22,11 +22,9 @@ interface IProps {
 }
 
 export default class RoomSearch extends React.PureComponent<IProps> {
-    private readonly dispatcherRef: string;
-
-    public constructor(props: IProps) {
-        super(props);
+    private dispatcherRef?: string;
 
+    public componentDidMount(): void {
         this.dispatcherRef = defaultDispatcher.register(this.onAction);
     }
 
diff --git a/src/components/structures/RoomStatusBar.tsx b/src/components/structures/RoomStatusBar.tsx
index bd236f2286..76f3b0c229 100644
--- a/src/components/structures/RoomStatusBar.tsx
+++ b/src/components/structures/RoomStatusBar.tsx
@@ -103,6 +103,8 @@ export default class RoomStatusBar extends React.PureComponent<IProps, IState> {
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
+
         const client = this.context;
         client.on(ClientEvent.Sync, this.onSyncStateChange);
         client.on(RoomEvent.LocalEchoUpdated, this.onRoomLocalEchoUpdated);
diff --git a/src/components/structures/RoomView.tsx b/src/components/structures/RoomView.tsx
index 486a7fb652..520760713c 100644
--- a/src/components/structures/RoomView.tsx
+++ b/src/components/structures/RoomView.tsx
@@ -351,8 +351,8 @@ export class RoomView extends React.Component<IRoomProps, IRoomState> {
     private static e2eStatusCache = new Map<string, E2EStatus>();
 
     private readonly askToJoinEnabled: boolean;
-    private readonly dispatcherRef: string;
-    private settingWatchers: string[];
+    private dispatcherRef?: string;
+    private settingWatchers: string[] = [];
 
     private unmounted = false;
     private permalinkCreators: Record<string, RoomPermalinkCreator> = {};
@@ -418,62 +418,6 @@ export class RoomView extends React.Component<IRoomProps, IRoomState> {
             promptAskToJoin: false,
             viewRoomOpts: { buttons: [] },
         };
-
-        this.dispatcherRef = dis.register(this.onAction);
-        context.client.on(ClientEvent.Room, this.onRoom);
-        context.client.on(RoomEvent.Timeline, this.onRoomTimeline);
-        context.client.on(RoomEvent.TimelineReset, this.onRoomTimelineReset);
-        context.client.on(RoomEvent.Name, this.onRoomName);
-        context.client.on(RoomStateEvent.Events, this.onRoomStateEvents);
-        context.client.on(RoomStateEvent.Update, this.onRoomStateUpdate);
-        context.client.on(RoomEvent.MyMembership, this.onMyMembership);
-        context.client.on(CryptoEvent.KeyBackupStatus, this.onKeyBackupStatus);
-        context.client.on(CryptoEvent.UserTrustStatusChanged, this.onUserVerificationChanged);
-        context.client.on(CryptoEvent.KeysChanged, this.onCrossSigningKeysChanged);
-        context.client.on(MatrixEventEvent.Decrypted, this.onEventDecrypted);
-        // Start listening for RoomViewStore updates
-        context.roomViewStore.on(UPDATE_EVENT, this.onRoomViewStoreUpdate);
-
-        context.rightPanelStore.on(UPDATE_EVENT, this.onRightPanelStoreUpdate);
-
-        WidgetEchoStore.on(UPDATE_EVENT, this.onWidgetEchoStoreUpdate);
-        context.widgetStore.on(UPDATE_EVENT, this.onWidgetStoreUpdate);
-
-        CallStore.instance.on(CallStoreEvent.ConnectedCalls, this.onConnectedCalls);
-
-        this.props.resizeNotifier.on("isResizing", this.onIsResizing);
-
-        this.settingWatchers = [
-            SettingsStore.watchSetting("layout", null, (...[, , , value]) =>
-                this.setState({ layout: value as Layout }),
-            ),
-            SettingsStore.watchSetting("lowBandwidth", null, (...[, , , value]) =>
-                this.setState({ lowBandwidth: value as boolean }),
-            ),
-            SettingsStore.watchSetting("alwaysShowTimestamps", null, (...[, , , value]) =>
-                this.setState({ alwaysShowTimestamps: value as boolean }),
-            ),
-            SettingsStore.watchSetting("showTwelveHourTimestamps", null, (...[, , , value]) =>
-                this.setState({ showTwelveHourTimestamps: value as boolean }),
-            ),
-            SettingsStore.watchSetting(TimezoneHandler.USER_TIMEZONE_KEY, null, (...[, , , value]) =>
-                this.setState({ userTimezone: value as string }),
-            ),
-            SettingsStore.watchSetting("readMarkerInViewThresholdMs", null, (...[, , , value]) =>
-                this.setState({ readMarkerInViewThresholdMs: value as number }),
-            ),
-            SettingsStore.watchSetting("readMarkerOutOfViewThresholdMs", null, (...[, , , value]) =>
-                this.setState({ readMarkerOutOfViewThresholdMs: value as number }),
-            ),
-            SettingsStore.watchSetting("showHiddenEventsInTimeline", null, (...[, , , value]) =>
-                this.setState({ showHiddenEvents: value as boolean }),
-            ),
-            SettingsStore.watchSetting("urlPreviewsEnabled", null, this.onUrlPreviewsEnabledChange),
-            SettingsStore.watchSetting("urlPreviewsEnabled_e2ee", null, this.onUrlPreviewsEnabledChange),
-            SettingsStore.watchSetting("feature_dynamic_room_predecessors", null, (...[, , , value]) =>
-                this.setState({ msc3946ProcessDynamicPredecessor: value as boolean }),
-            ),
-        ];
     }
 
     private onIsResizing = (resizing: boolean): void => {
@@ -904,6 +848,66 @@ export class RoomView extends React.Component<IRoomProps, IRoomState> {
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
+
+        this.dispatcherRef = dis.register(this.onAction);
+        if (this.context.client) {
+            this.context.client.on(ClientEvent.Room, this.onRoom);
+            this.context.client.on(RoomEvent.Timeline, this.onRoomTimeline);
+            this.context.client.on(RoomEvent.TimelineReset, this.onRoomTimelineReset);
+            this.context.client.on(RoomEvent.Name, this.onRoomName);
+            this.context.client.on(RoomStateEvent.Events, this.onRoomStateEvents);
+            this.context.client.on(RoomStateEvent.Update, this.onRoomStateUpdate);
+            this.context.client.on(RoomEvent.MyMembership, this.onMyMembership);
+            this.context.client.on(CryptoEvent.KeyBackupStatus, this.onKeyBackupStatus);
+            this.context.client.on(CryptoEvent.UserTrustStatusChanged, this.onUserVerificationChanged);
+            this.context.client.on(CryptoEvent.KeysChanged, this.onCrossSigningKeysChanged);
+            this.context.client.on(MatrixEventEvent.Decrypted, this.onEventDecrypted);
+        }
+        // Start listening for RoomViewStore updates
+        this.context.roomViewStore.on(UPDATE_EVENT, this.onRoomViewStoreUpdate);
+
+        this.context.rightPanelStore.on(UPDATE_EVENT, this.onRightPanelStoreUpdate);
+
+        WidgetEchoStore.on(UPDATE_EVENT, this.onWidgetEchoStoreUpdate);
+        this.context.widgetStore.on(UPDATE_EVENT, this.onWidgetStoreUpdate);
+
+        CallStore.instance.on(CallStoreEvent.ConnectedCalls, this.onConnectedCalls);
+
+        this.props.resizeNotifier.on("isResizing", this.onIsResizing);
+
+        this.settingWatchers = [
+            SettingsStore.watchSetting("layout", null, (...[, , , value]) =>
+                this.setState({ layout: value as Layout }),
+            ),
+            SettingsStore.watchSetting("lowBandwidth", null, (...[, , , value]) =>
+                this.setState({ lowBandwidth: value as boolean }),
+            ),
+            SettingsStore.watchSetting("alwaysShowTimestamps", null, (...[, , , value]) =>
+                this.setState({ alwaysShowTimestamps: value as boolean }),
+            ),
+            SettingsStore.watchSetting("showTwelveHourTimestamps", null, (...[, , , value]) =>
+                this.setState({ showTwelveHourTimestamps: value as boolean }),
+            ),
+            SettingsStore.watchSetting(TimezoneHandler.USER_TIMEZONE_KEY, null, (...[, , , value]) =>
+                this.setState({ userTimezone: value as string }),
+            ),
+            SettingsStore.watchSetting("readMarkerInViewThresholdMs", null, (...[, , , value]) =>
+                this.setState({ readMarkerInViewThresholdMs: value as number }),
+            ),
+            SettingsStore.watchSetting("readMarkerOutOfViewThresholdMs", null, (...[, , , value]) =>
+                this.setState({ readMarkerOutOfViewThresholdMs: value as number }),
+            ),
+            SettingsStore.watchSetting("showHiddenEventsInTimeline", null, (...[, , , value]) =>
+                this.setState({ showHiddenEvents: value as boolean }),
+            ),
+            SettingsStore.watchSetting("urlPreviewsEnabled", null, this.onUrlPreviewsEnabledChange),
+            SettingsStore.watchSetting("urlPreviewsEnabled_e2ee", null, this.onUrlPreviewsEnabledChange),
+            SettingsStore.watchSetting("feature_dynamic_room_predecessors", null, (...[, , , value]) =>
+                this.setState({ msc3946ProcessDynamicPredecessor: value as boolean }),
+            ),
+        ];
+
         this.onRoomViewStoreUpdate(true);
 
         const call = this.getCallForRoom();
diff --git a/src/components/structures/ScrollPanel.tsx b/src/components/structures/ScrollPanel.tsx
index d072c322ce..b354f6b005 100644
--- a/src/components/structures/ScrollPanel.tsx
+++ b/src/components/structures/ScrollPanel.tsx
@@ -191,12 +191,12 @@ export default class ScrollPanel extends React.Component<IProps> {
     public constructor(props: IProps) {
         super(props);
 
-        this.props.resizeNotifier?.on("middlePanelResizedNoisy", this.onResize);
-
         this.resetScrollState();
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
+        this.props.resizeNotifier?.on("middlePanelResizedNoisy", this.onResize);
         this.checkScroll();
     }
 
diff --git a/src/components/structures/SpaceRoomView.tsx b/src/components/structures/SpaceRoomView.tsx
index 4f0c895233..3ea2a03c1a 100644
--- a/src/components/structures/SpaceRoomView.tsx
+++ b/src/components/structures/SpaceRoomView.tsx
@@ -599,7 +599,7 @@ export default class SpaceRoomView extends React.PureComponent<IProps, IState> {
     public static contextType = MatrixClientContext;
     public declare context: React.ContextType<typeof MatrixClientContext>;
 
-    private readonly dispatcherRef: string;
+    private dispatcherRef?: string;
 
     public constructor(props: IProps, context: React.ContextType<typeof MatrixClientContext>) {
         super(props, context);
@@ -621,12 +621,11 @@ export default class SpaceRoomView extends React.PureComponent<IProps, IState> {
             showRightPanel: RightPanelStore.instance.isOpenForRoom(this.props.space.roomId),
             myMembership: this.props.space.getMyMembership(),
         };
-
-        this.dispatcherRef = defaultDispatcher.register(this.onAction);
-        RightPanelStore.instance.on(UPDATE_EVENT, this.onRightPanelStoreUpdate);
     }
 
     public componentDidMount(): void {
+        this.dispatcherRef = defaultDispatcher.register(this.onAction);
+        RightPanelStore.instance.on(UPDATE_EVENT, this.onRightPanelStoreUpdate);
         this.context.on(RoomEvent.MyMembership, this.onMyMembership);
     }
 
diff --git a/src/components/structures/ThreadView.tsx b/src/components/structures/ThreadView.tsx
index 8d2a286de1..be538a6669 100644
--- a/src/components/structures/ThreadView.tsx
+++ b/src/components/structures/ThreadView.tsx
@@ -78,7 +78,7 @@ export default class ThreadView extends React.Component<IProps, IState> {
     public declare context: React.ContextType<typeof RoomContext>;
 
     private dispatcherRef?: string;
-    private readonly layoutWatcherRef: string;
+    private layoutWatcherRef?: string;
     private timelinePanel = createRef<TimelinePanel>();
     private card = createRef<HTMLDivElement>();
 
@@ -91,7 +91,6 @@ export default class ThreadView extends React.Component<IProps, IState> {
         this.setEventId(this.props.mxEvent);
         const thread = this.props.room.getThread(this.eventId) ?? undefined;
 
-        this.setupThreadListeners(thread);
         this.state = {
             layout: SettingsStore.getValue("layout"),
             narrow: false,
@@ -100,13 +99,15 @@ export default class ThreadView extends React.Component<IProps, IState> {
                 return ev.isRelation(THREAD_RELATION_TYPE.name) && !ev.status;
             }),
         };
+    }
+
+    public componentDidMount(): void {
+        this.setupThreadListeners(this.state.thread);
 
         this.layoutWatcherRef = SettingsStore.watchSetting("layout", null, (...[, , , value]) =>
             this.setState({ layout: value as Layout }),
         );
-    }
 
-    public componentDidMount(): void {
         if (this.state.thread) {
             this.postThreadUpdate(this.state.thread);
         }
diff --git a/src/components/structures/TimelinePanel.tsx b/src/components/structures/TimelinePanel.tsx
index 846fc56d17..68b65965f5 100644
--- a/src/components/structures/TimelinePanel.tsx
+++ b/src/components/structures/TimelinePanel.tsx
@@ -248,7 +248,7 @@ class TimelinePanel extends React.Component<IProps, IState> {
     private lastRMSentEventId: string | null | undefined = undefined;
 
     private readonly messagePanel = createRef<MessagePanel>();
-    private readonly dispatcherRef: string;
+    private dispatcherRef?: string;
     private timelineWindow?: TimelineWindow;
     private overlayTimelineWindow?: TimelineWindow;
     private unmounted = false;
@@ -291,6 +291,10 @@ class TimelinePanel extends React.Component<IProps, IState> {
             readMarkerInViewThresholdMs: SettingsStore.getValue("readMarkerInViewThresholdMs"),
             readMarkerOutOfViewThresholdMs: SettingsStore.getValue("readMarkerOutOfViewThresholdMs"),
         };
+    }
+
+    public componentDidMount(): void {
+        this.unmounted = false;
 
         this.dispatcherRef = dis.register(this.onAction);
         const cli = MatrixClientPeg.safeGet();
@@ -312,9 +316,7 @@ class TimelinePanel extends React.Component<IProps, IState> {
         cli.on(ClientEvent.Sync, this.onSync);
 
         this.props.timelineSet.room?.on(ThreadEvent.Update, this.onThreadUpdate);
-    }
 
-    public componentDidMount(): void {
         if (this.props.manageReadReceipts) {
             this.updateReadReceiptOnUserActivity();
         }
diff --git a/src/components/structures/ToastContainer.tsx b/src/components/structures/ToastContainer.tsx
index 8c572442a0..3e5b4a4474 100644
--- a/src/components/structures/ToastContainer.tsx
+++ b/src/components/structures/ToastContainer.tsx
@@ -24,12 +24,11 @@ export default class ToastContainer extends React.Component<{}, IState> {
             toasts: ToastStore.sharedInstance().getToasts(),
             countSeen: ToastStore.sharedInstance().getCountSeen(),
         };
+    }
 
-        // Start listening here rather than in componentDidMount because
-        // toasts may dismiss themselves in their didMount if they find
-        // they're already irrelevant by the time they're mounted, and
-        // our own componentDidMount is too late.
+    public componentDidMount(): void {
         ToastStore.sharedInstance().on("update", this.onToastStoreUpdate);
+        this.onToastStoreUpdate();
     }
 
     public componentWillUnmount(): void {
diff --git a/src/components/structures/UploadBar.tsx b/src/components/structures/UploadBar.tsx
index 93ce6d6bf2..01ecae96dc 100644
--- a/src/components/structures/UploadBar.tsx
+++ b/src/components/structures/UploadBar.tsx
@@ -46,7 +46,7 @@ function isUploadPayload(payload: ActionPayload): payload is UploadPayload {
 
 export default class UploadBar extends React.PureComponent<IProps, IState> {
     private dispatcherRef: Optional<string>;
-    private mounted = false;
+    private unmounted = false;
 
     public constructor(props: IProps) {
         super(props);
@@ -57,12 +57,12 @@ export default class UploadBar extends React.PureComponent<IProps, IState> {
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
         this.dispatcherRef = dis.register(this.onAction);
-        this.mounted = true;
     }
 
     public componentWillUnmount(): void {
-        this.mounted = false;
+        this.unmounted = true;
         dis.unregister(this.dispatcherRef!);
     }
 
@@ -83,7 +83,7 @@ export default class UploadBar extends React.PureComponent<IProps, IState> {
     }
 
     private onAction = (payload: ActionPayload): void => {
-        if (!this.mounted) return;
+        if (this.unmounted) return;
         if (isUploadPayload(payload)) {
             this.setState(this.calculateState());
         }
diff --git a/src/components/structures/UserMenu.tsx b/src/components/structures/UserMenu.tsx
index 84bd93cc36..b2c7990746 100644
--- a/src/components/structures/UserMenu.tsx
+++ b/src/components/structures/UserMenu.tsx
@@ -96,9 +96,6 @@ export default class UserMenu extends React.Component<IProps, IState> {
             selectedSpace: SpaceStore.instance.activeSpaceRoom,
             showLiveAvatarAddon: this.context.voiceBroadcastRecordingsStore.hasCurrent(),
         };
-
-        OwnProfileStore.instance.on(UPDATE_EVENT, this.onProfileUpdate);
-        SpaceStore.instance.on(UPDATE_SELECTED_SPACE, this.onSelectedSpaceUpdate);
     }
 
     private get hasHomePage(): boolean {
@@ -112,6 +109,8 @@ export default class UserMenu extends React.Component<IProps, IState> {
     };
 
     public componentDidMount(): void {
+        OwnProfileStore.instance.on(UPDATE_EVENT, this.onProfileUpdate);
+        SpaceStore.instance.on(UPDATE_SELECTED_SPACE, this.onSelectedSpaceUpdate);
         this.context.voiceBroadcastRecordingsStore.on(
             VoiceBroadcastRecordingsStoreEvent.CurrentChanged,
             this.onCurrentVoiceBroadcastRecordingChanged,
diff --git a/src/components/structures/auth/CompleteSecurity.tsx b/src/components/structures/auth/CompleteSecurity.tsx
index a74e07692d..ec65a62cef 100644
--- a/src/components/structures/auth/CompleteSecurity.tsx
+++ b/src/components/structures/auth/CompleteSecurity.tsx
@@ -29,11 +29,15 @@ export default class CompleteSecurity extends React.Component<IProps, IState> {
     public constructor(props: IProps) {
         super(props);
         const store = SetupEncryptionStore.sharedInstance();
-        store.on("update", this.onStoreUpdate);
         store.start();
         this.state = { phase: store.phase, lostKeys: store.lostKeys() };
     }
 
+    public componentDidMount(): void {
+        const store = SetupEncryptionStore.sharedInstance();
+        store.on("update", this.onStoreUpdate);
+    }
+
     private onStoreUpdate = (): void => {
         const store = SetupEncryptionStore.sharedInstance();
         this.setState({ phase: store.phase, lostKeys: store.lostKeys() });
diff --git a/src/components/structures/auth/Login.tsx b/src/components/structures/auth/Login.tsx
index abbba0f970..0a14450e63 100644
--- a/src/components/structures/auth/Login.tsx
+++ b/src/components/structures/auth/Login.tsx
@@ -134,6 +134,7 @@ export default class LoginComponent extends React.PureComponent<IProps, IState>
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
         this.initLoginLogic(this.props.serverConfig);
     }
 
diff --git a/src/components/structures/auth/SetupEncryptionBody.tsx b/src/components/structures/auth/SetupEncryptionBody.tsx
index 666313321a..32528fc7e3 100644
--- a/src/components/structures/auth/SetupEncryptionBody.tsx
+++ b/src/components/structures/auth/SetupEncryptionBody.tsx
@@ -39,7 +39,6 @@ export default class SetupEncryptionBody extends React.Component<IProps, IState>
     public constructor(props: IProps) {
         super(props);
         const store = SetupEncryptionStore.sharedInstance();
-        store.on("update", this.onStoreUpdate);
         store.start();
         this.state = {
             phase: store.phase,
@@ -52,6 +51,11 @@ export default class SetupEncryptionBody extends React.Component<IProps, IState>
         };
     }
 
+    public componentDidMount(): void {
+        const store = SetupEncryptionStore.sharedInstance();
+        store.on("update", this.onStoreUpdate);
+    }
+
     private onStoreUpdate = (): void => {
         const store = SetupEncryptionStore.sharedInstance();
         if (store.phase === Phase.Finished) {
diff --git a/src/components/views/audio_messages/AudioPlayerBase.tsx b/src/components/views/audio_messages/AudioPlayerBase.tsx
index 70e30dccca..601611e422 100644
--- a/src/components/views/audio_messages/AudioPlayerBase.tsx
+++ b/src/components/views/audio_messages/AudioPlayerBase.tsx
@@ -41,7 +41,9 @@ export default abstract class AudioPlayerBase<T extends IProps = IProps> extends
         this.state = {
             playbackPhase: this.props.playback.currentState,
         };
+    }
 
+    public componentDidMount(): void {
         // We don't need to de-register: the class handles this for us internally
         this.props.playback.on(UPDATE_EVENT, this.onPlaybackUpdate);
 
diff --git a/src/components/views/audio_messages/Clock.tsx b/src/components/views/audio_messages/Clock.tsx
index 56661c7a0c..ca72d29a05 100644
--- a/src/components/views/audio_messages/Clock.tsx
+++ b/src/components/views/audio_messages/Clock.tsx
@@ -27,10 +27,6 @@ export default class Clock extends React.Component<Props> {
         formatFn: formatSeconds,
     };
 
-    public constructor(props: Props) {
-        super(props);
-    }
-
     public shouldComponentUpdate(nextProps: Readonly<Props>): boolean {
         const currentFloor = Math.floor(this.props.seconds);
         const nextFloor = Math.floor(nextProps.seconds);
diff --git a/src/components/views/audio_messages/DurationClock.tsx b/src/components/views/audio_messages/DurationClock.tsx
index e495098144..3794ab9a4f 100644
--- a/src/components/views/audio_messages/DurationClock.tsx
+++ b/src/components/views/audio_messages/DurationClock.tsx
@@ -33,6 +33,9 @@ export default class DurationClock extends React.PureComponent<IProps, IState> {
             // member property to track "did we get a duration".
             durationSeconds: this.props.playback.clockInfo.durationSeconds,
         };
+    }
+
+    public componentDidMount(): void {
         this.props.playback.clockInfo.liveData.onUpdate(this.onTimeUpdate);
     }
 
diff --git a/src/components/views/audio_messages/PlayPauseButton.tsx b/src/components/views/audio_messages/PlayPauseButton.tsx
index 1053a89eea..1cd2d168b4 100644
--- a/src/components/views/audio_messages/PlayPauseButton.tsx
+++ b/src/components/views/audio_messages/PlayPauseButton.tsx
@@ -26,10 +26,6 @@ type Props = Omit<ButtonProps<"div">, "title" | "onClick" | "disabled" | "elemen
  * to be displayed in reference to a recording.
  */
 export default class PlayPauseButton extends React.PureComponent<Props> {
-    public constructor(props: Props) {
-        super(props);
-    }
-
     private onClick = (): void => {
         // noinspection JSIgnoredPromiseFromCall
         this.toggleState();
diff --git a/src/components/views/audio_messages/PlaybackClock.tsx b/src/components/views/audio_messages/PlaybackClock.tsx
index 8de3cb71e6..b3d736758b 100644
--- a/src/components/views/audio_messages/PlaybackClock.tsx
+++ b/src/components/views/audio_messages/PlaybackClock.tsx
@@ -43,6 +43,9 @@ export default class PlaybackClock extends React.PureComponent<IProps, IState> {
             durationSeconds: this.props.playback.clockInfo.durationSeconds,
             playbackPhase: PlaybackState.Stopped, // assume not started, so full clock
         };
+    }
+
+    public componentDidMount(): void {
         this.props.playback.on(UPDATE_EVENT, this.onPlaybackUpdate);
         this.props.playback.clockInfo.liveData.onUpdate(this.onTimeUpdate);
     }
diff --git a/src/components/views/audio_messages/PlaybackWaveform.tsx b/src/components/views/audio_messages/PlaybackWaveform.tsx
index 5f59289879..0f95f7084b 100644
--- a/src/components/views/audio_messages/PlaybackWaveform.tsx
+++ b/src/components/views/audio_messages/PlaybackWaveform.tsx
@@ -34,7 +34,9 @@ export default class PlaybackWaveform extends React.PureComponent<IProps, IState
             heights: this.toHeights(this.props.playback.waveform),
             progress: 0, // default no progress
         };
+    }
 
+    public componentDidMount(): void {
         this.props.playback.waveformData.onUpdate(this.onWaveformUpdate);
         this.props.playback.clockInfo.liveData.onUpdate(this.onTimeUpdate);
     }
diff --git a/src/components/views/audio_messages/SeekBar.tsx b/src/components/views/audio_messages/SeekBar.tsx
index cbfab888bf..f56bfee9af 100644
--- a/src/components/views/audio_messages/SeekBar.tsx
+++ b/src/components/views/audio_messages/SeekBar.tsx
@@ -55,7 +55,9 @@ export default class SeekBar extends React.PureComponent<IProps, IState> {
         this.state = {
             percentage: percentageOf(this.props.playback.timeSeconds, 0, this.props.playback.durationSeconds),
         };
+    }
 
+    public componentDidMount(): void {
         // We don't need to de-register: the class handles this for us internally
         this.props.playback.liveData.onUpdate(() => this.animationFrameFn.mark());
     }
diff --git a/src/components/views/auth/InteractiveAuthEntryComponents.tsx b/src/components/views/auth/InteractiveAuthEntryComponents.tsx
index 44ccd3a30e..b1360f5560 100644
--- a/src/components/views/auth/InteractiveAuthEntryComponents.tsx
+++ b/src/components/views/auth/InteractiveAuthEntryComponents.tsx
@@ -801,7 +801,6 @@ export class SSOAuthEntry extends React.Component<ISSOAuthEntryProps, ISSOAuthEn
         this.ssoUrl = props.matrixClient.getFallbackAuthUrl(this.props.loginType, this.props.authSessionId);
 
         this.popupWindow = null;
-        window.addEventListener("message", this.onReceiveMessage);
 
         this.state = {
             phase: SSOAuthEntry.PHASE_PREAUTH,
@@ -810,6 +809,7 @@ export class SSOAuthEntry extends React.Component<ISSOAuthEntryProps, ISSOAuthEn
     }
 
     public componentDidMount(): void {
+        window.addEventListener("message", this.onReceiveMessage);
         this.props.onPhaseChange(SSOAuthEntry.PHASE_PREAUTH);
     }
 
@@ -918,10 +918,10 @@ export class FallbackAuthEntry<T = {}> extends React.Component<IAuthEntryProps &
         // we have to make the user click a button, as browsers will block
         // the popup if we open it immediately.
         this.popupWindow = null;
-        window.addEventListener("message", this.onReceiveMessage);
     }
 
     public componentDidMount(): void {
+        window.addEventListener("message", this.onReceiveMessage);
         this.props.onPhaseChange(DEFAULT_PHASE);
     }
 
diff --git a/src/components/views/auth/LoginWithQRFlow.tsx b/src/components/views/auth/LoginWithQRFlow.tsx
index 5805df967b..33d51f6952 100644
--- a/src/components/views/auth/LoginWithQRFlow.tsx
+++ b/src/components/views/auth/LoginWithQRFlow.tsx
@@ -41,10 +41,6 @@ interface Props {
 export default class LoginWithQRFlow extends React.Component<Props> {
     private checkCodeInput = createRef<HTMLInputElement>();
 
-    public constructor(props: Props) {
-        super(props);
-    }
-
     private handleClick = (type: Click): ((e: React.FormEvent) => Promise<void>) => {
         return async (e: React.FormEvent): Promise<void> => {
             e.preventDefault();
diff --git a/src/components/views/context_menus/GenericElementContextMenu.tsx b/src/components/views/context_menus/GenericElementContextMenu.tsx
index 42ed8ce5be..afb39d6ebe 100644
--- a/src/components/views/context_menus/GenericElementContextMenu.tsx
+++ b/src/components/views/context_menus/GenericElementContextMenu.tsx
@@ -20,10 +20,6 @@ interface IProps {
  * menu.
  */
 export default class GenericElementContextMenu extends React.Component<IProps> {
-    public constructor(props: IProps) {
-        super(props);
-    }
-
     public componentDidMount(): void {
         window.addEventListener("resize", this.resize);
     }
diff --git a/src/components/views/context_menus/LegacyCallContextMenu.tsx b/src/components/views/context_menus/LegacyCallContextMenu.tsx
index 817b4632e8..e6bb191df8 100644
--- a/src/components/views/context_menus/LegacyCallContextMenu.tsx
+++ b/src/components/views/context_menus/LegacyCallContextMenu.tsx
@@ -17,10 +17,6 @@ interface IProps extends IContextMenuProps {
 }
 
 export default class LegacyCallContextMenu extends React.Component<IProps> {
-    public constructor(props: IProps) {
-        super(props);
-    }
-
     public onHoldClick = (): void => {
         this.props.call.setRemoteOnHold(true);
         this.props.onFinished();
diff --git a/src/components/views/dialogs/BugReportDialog.tsx b/src/components/views/dialogs/BugReportDialog.tsx
index 22a7efacb9..373f30d3ae 100644
--- a/src/components/views/dialogs/BugReportDialog.tsx
+++ b/src/components/views/dialogs/BugReportDialog.tsx
@@ -64,6 +64,11 @@ export default class BugReportDialog extends React.Component<IProps, IState> {
 
         this.unmounted = false;
         this.issueRef = React.createRef();
+    }
+
+    public componentDidMount(): void {
+        this.unmounted = false;
+        this.issueRef.current?.focus();
 
         // Get all of the extra info dumped to the console when someone is about
         // to send debug logs. Since this is a fire and forget action, we do
@@ -76,10 +81,6 @@ export default class BugReportDialog extends React.Component<IProps, IState> {
         });
     }
 
-    public componentDidMount(): void {
-        this.issueRef.current?.focus();
-    }
-
     public componentWillUnmount(): void {
         this.unmounted = true;
     }
diff --git a/src/components/views/dialogs/CreateRoomDialog.tsx b/src/components/views/dialogs/CreateRoomDialog.tsx
index c5a8080e3f..990efdda71 100644
--- a/src/components/views/dialogs/CreateRoomDialog.tsx
+++ b/src/components/views/dialogs/CreateRoomDialog.tsx
@@ -113,14 +113,6 @@ export default class CreateRoomDialog extends React.Component<IProps, IState> {
             nameIsValid: false,
             canChangeEncryption: false,
         };
-
-        checkUserIsAllowedToChangeEncryption(cli, Preset.PrivateChat).then(({ allowChange, forcedValue }) =>
-            this.setState((state) => ({
-                canChangeEncryption: allowChange,
-                // override with forcedValue if it is set
-                isEncrypted: forcedValue ?? state.isEncrypted,
-            })),
-        );
     }
 
     private roomCreateOptions(): IOpts {
@@ -160,6 +152,15 @@ export default class CreateRoomDialog extends React.Component<IProps, IState> {
     }
 
     public componentDidMount(): void {
+        const cli = MatrixClientPeg.safeGet();
+        checkUserIsAllowedToChangeEncryption(cli, Preset.PrivateChat).then(({ allowChange, forcedValue }) =>
+            this.setState((state) => ({
+                canChangeEncryption: allowChange,
+                // override with forcedValue if it is set
+                isEncrypted: forcedValue ?? state.isEncrypted,
+            })),
+        );
+
         // move focus to first field when showing dialog
         this.nameField.current?.focus();
     }
diff --git a/src/components/views/dialogs/DeactivateAccountDialog.tsx b/src/components/views/dialogs/DeactivateAccountDialog.tsx
index fbcd26d38f..d68c931cc1 100644
--- a/src/components/views/dialogs/DeactivateAccountDialog.tsx
+++ b/src/components/views/dialogs/DeactivateAccountDialog.tsx
@@ -58,7 +58,9 @@ export default class DeactivateAccountDialog extends React.Component<IProps, ISt
             authData: null, // for UIA
             authEnabled: true, // see usages for information
         };
+    }
 
+    public componentDidMount(): void {
         this.initAuth(/* shouldErase= */ false);
     }
 
diff --git a/src/components/views/dialogs/IncomingSasDialog.tsx b/src/components/views/dialogs/IncomingSasDialog.tsx
index c33ab7c267..4e273f62f7 100644
--- a/src/components/views/dialogs/IncomingSasDialog.tsx
+++ b/src/components/views/dialogs/IncomingSasDialog.tsx
@@ -63,6 +63,9 @@ export default class IncomingSasDialog extends React.Component<IProps, IState> {
             opponentProfileError: null,
             sas: null,
         };
+    }
+
+    public componentDidMount(): void {
         this.props.verifier.on(VerifierEvent.ShowSas, this.onVerifierShowSas);
         this.props.verifier.on(VerifierEvent.Cancel, this.onVerifierCancel);
         this.fetchOpponentProfile();
diff --git a/src/components/views/dialogs/InviteDialog.tsx b/src/components/views/dialogs/InviteDialog.tsx
index 8e1d49c138..35e04fb12e 100644
--- a/src/components/views/dialogs/InviteDialog.tsx
+++ b/src/components/views/dialogs/InviteDialog.tsx
@@ -397,6 +397,7 @@ export default class InviteDialog extends React.PureComponent<Props, IInviteDial
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
         this.encryptionByDefault = privateShouldBeEncrypted(MatrixClientPeg.safeGet());
 
         if (this.props.initialText) {
diff --git a/src/components/views/dialogs/LogoutDialog.tsx b/src/components/views/dialogs/LogoutDialog.tsx
index bc9ccb3f78..51dc664fb4 100644
--- a/src/components/views/dialogs/LogoutDialog.tsx
+++ b/src/components/views/dialogs/LogoutDialog.tsx
@@ -81,9 +81,10 @@ export default class LogoutDialog extends React.Component<IProps, IState> {
         this.state = {
             backupStatus: BackupStatus.LOADING,
         };
+    }
 
-        // we can't call setState() immediately, so wait a beat
-        window.setTimeout(() => this.startLoadBackupStatus(), 0);
+    public componentDidMount(): void {
+        this.startLoadBackupStatus();
     }
 
     /** kick off the asynchronous calls to populate `state.backupStatus` in the background */
diff --git a/src/components/views/dialogs/VerificationRequestDialog.tsx b/src/components/views/dialogs/VerificationRequestDialog.tsx
index 50644ccf30..d2ea83f2af 100644
--- a/src/components/views/dialogs/VerificationRequestDialog.tsx
+++ b/src/components/views/dialogs/VerificationRequestDialog.tsx
@@ -32,6 +32,9 @@ export default class VerificationRequestDialog extends React.Component<IProps, I
         this.state = {
             verificationRequest: this.props.verificationRequest,
         };
+    }
+
+    public componentDidMount(): void {
         this.props.verificationRequestPromise?.then((r) => {
             this.setState({ verificationRequest: r });
         });
diff --git a/src/components/views/elements/AppTile.tsx b/src/components/views/elements/AppTile.tsx
index 8f5aa732be..dae452fd5d 100644
--- a/src/components/views/elements/AppTile.tsx
+++ b/src/components/views/elements/AppTile.tsx
@@ -134,29 +134,20 @@ export default class AppTile extends React.Component<IProps, IState> {
     private iframe?: HTMLIFrameElement; // ref to the iframe (callback style)
     private allowedWidgetsWatchRef?: string;
     private persistKey: string;
-    private sgWidget: StopGapWidget | null;
+    private sgWidget?: StopGapWidget;
     private dispatcherRef?: string;
     private unmounted = false;
 
     public constructor(props: IProps, context: ContextType<typeof MatrixClientContext>) {
         super(props, context);
 
-        // Tiles in miniMode are floating, and therefore not docked
-        if (!this.props.miniMode) {
-            ActiveWidgetStore.instance.dockWidget(
-                this.props.app.id,
-                isAppWidget(this.props.app) ? this.props.app.roomId : null,
-            );
-        }
-
         // The key used for PersistedElement
         this.persistKey = getPersistKey(WidgetUtils.getWidgetUid(this.props.app));
         try {
             this.sgWidget = new StopGapWidget(this.props);
-            this.setupSgListeners();
         } catch (e) {
             logger.log("Failed to construct widget", e);
-            this.sgWidget = null;
+            this.sgWidget = undefined;
         }
 
         this.state = this.getNewState(props);
@@ -303,6 +294,20 @@ export default class AppTile extends React.Component<IProps, IState> {
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
+
+        // Tiles in miniMode are floating, and therefore not docked
+        if (!this.props.miniMode) {
+            ActiveWidgetStore.instance.dockWidget(
+                this.props.app.id,
+                isAppWidget(this.props.app) ? this.props.app.roomId : null,
+            );
+        }
+
+        if (this.sgWidget) {
+            this.setupSgListeners();
+        }
+
         // Only fetch IM token on mount if we're showing and have permission to load
         if (this.sgWidget && this.state.hasPermissionToLoad) {
             this.startWidget();
@@ -374,7 +379,7 @@ export default class AppTile extends React.Component<IProps, IState> {
             this.startWidget();
         } catch (e) {
             logger.error("Failed to construct widget", e);
-            this.sgWidget = null;
+            this.sgWidget = undefined;
         }
     }
 
@@ -607,7 +612,7 @@ export default class AppTile extends React.Component<IProps, IState> {
     };
 
     public render(): React.ReactNode {
-        let appTileBody: JSX.Element;
+        let appTileBody: JSX.Element | undefined;
 
         // Note that there is advice saying allow-scripts shouldn't be used with allow-same-origin
         // because that would allow the iframe to programmatically remove the sandbox attribute, but
@@ -650,7 +655,7 @@ export default class AppTile extends React.Component<IProps, IState> {
                     <AppWarning errorMsg={_t("widget|error_loading")} />
                 </div>
             );
-        } else if (!this.state.hasPermissionToLoad && this.props.room) {
+        } else if (!this.state.hasPermissionToLoad && this.props.room && this.sgWidget) {
             // only possible for room widgets, can assert this.props.room here
             const isEncrypted = this.context.isRoomEncrypted(this.props.room.roomId);
             appTileBody = (
@@ -677,7 +682,7 @@ export default class AppTile extends React.Component<IProps, IState> {
                         <AppWarning errorMsg={_t("widget|error_mixed_content")} />
                     </div>
                 );
-            } else {
+            } else if (this.sgWidget) {
                 appTileBody = (
                     <>
                         <div className={appTileBodyClass} style={appTileBodyStyles}>
diff --git a/src/components/views/elements/DesktopCapturerSourcePicker.tsx b/src/components/views/elements/DesktopCapturerSourcePicker.tsx
index 26b759bcb2..e1f1def836 100644
--- a/src/components/views/elements/DesktopCapturerSourcePicker.tsx
+++ b/src/components/views/elements/DesktopCapturerSourcePicker.tsx
@@ -41,10 +41,6 @@ export interface ExistingSourceIProps {
 }
 
 export class ExistingSource extends React.Component<ExistingSourceIProps> {
-    public constructor(props: ExistingSourceIProps) {
-        super(props);
-    }
-
     private onClick = (): void => {
         this.props.onSelect(this.props.source);
     };
diff --git a/src/components/views/elements/Dropdown.tsx b/src/components/views/elements/Dropdown.tsx
index c8802cd880..a7ce84163c 100644
--- a/src/components/views/elements/Dropdown.tsx
+++ b/src/components/views/elements/Dropdown.tsx
@@ -127,7 +127,9 @@ export default class Dropdown extends React.Component<DropdownProps, IState> {
             // the current search query
             searchQuery: "",
         };
+    }
 
+    public componentDidMount(): void {
         // Listen for all clicks on the document so we can close the
         // menu when the user clicks somewhere else
         document.addEventListener("click", this.onDocumentClick, false);
diff --git a/src/components/views/elements/LinkWithTooltip.tsx b/src/components/views/elements/LinkWithTooltip.tsx
index a9ca2606ae..016297d9f1 100644
--- a/src/components/views/elements/LinkWithTooltip.tsx
+++ b/src/components/views/elements/LinkWithTooltip.tsx
@@ -15,10 +15,6 @@ interface IProps extends Omit<React.ComponentProps<typeof TextWithTooltip>, "tab
 }
 
 export default class LinkWithTooltip extends React.Component<IProps> {
-    public constructor(props: IProps) {
-        super(props);
-    }
-
     public render(): React.ReactNode {
         const { children, tooltip, ...props } = this.props;
 
diff --git a/src/components/views/elements/PersistedElement.tsx b/src/components/views/elements/PersistedElement.tsx
index 20584f3794..2c87c8e7c6 100644
--- a/src/components/views/elements/PersistedElement.tsx
+++ b/src/components/views/elements/PersistedElement.tsx
@@ -79,7 +79,7 @@ interface IProps {
  */
 export default class PersistedElement extends React.Component<IProps> {
     private resizeObserver: ResizeObserver;
-    private dispatcherRef: string;
+    private dispatcherRef?: string;
     private childContainer?: HTMLDivElement;
     private child?: HTMLDivElement;
 
@@ -87,13 +87,6 @@ export default class PersistedElement extends React.Component<IProps> {
         super(props);
 
         this.resizeObserver = new ResizeObserver(this.repositionChild);
-        // Annoyingly, a resize observer is insufficient, since we also care
-        // about when the element moves on the screen without changing its
-        // dimensions. Doesn't look like there's a ResizeObserver equivalent
-        // for this, so we bodge it by listening for document resize and
-        // the timeline_resize action.
-        window.addEventListener("resize", this.repositionChild);
-        this.dispatcherRef = dis.register(this.onAction);
 
         if (this.props.moveRef) this.props.moveRef.current = this.repositionChild;
     }
@@ -132,6 +125,14 @@ export default class PersistedElement extends React.Component<IProps> {
     };
 
     public componentDidMount(): void {
+        // Annoyingly, a resize observer is insufficient, since we also care
+        // about when the element moves on the screen without changing its
+        // dimensions. Doesn't look like there's a ResizeObserver equivalent
+        // for this, so we bodge it by listening for document resize and
+        // the timeline_resize action.
+        window.addEventListener("resize", this.repositionChild);
+        this.dispatcherRef = dis.register(this.onAction);
+
         this.updateChild();
         this.renderApp();
     }
diff --git a/src/components/views/elements/PowerSelector.tsx b/src/components/views/elements/PowerSelector.tsx
index b600b2ba96..385d932b87 100644
--- a/src/components/views/elements/PowerSelector.tsx
+++ b/src/components/views/elements/PowerSelector.tsx
@@ -68,6 +68,7 @@ export default class PowerSelector<K extends undefined | string> extends React.C
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
         this.initStateFromProps();
     }
 
diff --git a/src/components/views/elements/ReplyChain.tsx b/src/components/views/elements/ReplyChain.tsx
index 4eb3707031..71846d6065 100644
--- a/src/components/views/elements/ReplyChain.tsx
+++ b/src/components/views/elements/ReplyChain.tsx
@@ -89,6 +89,7 @@ export default class ReplyChain extends React.Component<IProps, IState> {
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
         this.initialize();
         this.trySetExpandableQuotes();
     }
diff --git a/src/components/views/elements/TextWithTooltip.tsx b/src/components/views/elements/TextWithTooltip.tsx
index 34346cbe25..b589ce3635 100644
--- a/src/components/views/elements/TextWithTooltip.tsx
+++ b/src/components/views/elements/TextWithTooltip.tsx
@@ -16,10 +16,6 @@ interface IProps extends HTMLAttributes<HTMLSpanElement> {
 }
 
 export default class TextWithTooltip extends React.Component<IProps> {
-    public constructor(props: IProps) {
-        super(props);
-    }
-
     public render(): React.ReactNode {
         const { className, children, tooltip, tooltipProps } = this.props;
 
diff --git a/src/components/views/emojipicker/ReactionPicker.tsx b/src/components/views/emojipicker/ReactionPicker.tsx
index 2c2eb442a0..b62df99e25 100644
--- a/src/components/views/emojipicker/ReactionPicker.tsx
+++ b/src/components/views/emojipicker/ReactionPicker.tsx
@@ -37,6 +37,9 @@ class ReactionPicker extends React.Component<IProps, IState> {
         this.state = {
             selectedEmojis: new Set(Object.keys(this.getReactions())),
         };
+    }
+
+    public componentDidMount(): void {
         this.addListeners();
     }
 
diff --git a/src/components/views/messages/DateSeparator.tsx b/src/components/views/messages/DateSeparator.tsx
index 7996b3bebe..6aed04d8f9 100644
--- a/src/components/views/messages/DateSeparator.tsx
+++ b/src/components/views/messages/DateSeparator.tsx
@@ -58,7 +58,9 @@ export default class DateSeparator extends React.Component<IProps, IState> {
         this.state = {
             jumpToDateEnabled: SettingsStore.getValue("feature_jump_to_date"),
         };
+    }
 
+    public componentDidMount(): void {
         // We're using a watcher so the date headers in the timeline are updated
         // when the lab setting is toggled.
         this.settingWatcherRef = SettingsStore.watchSetting(
diff --git a/src/components/views/messages/MImageBody.tsx b/src/components/views/messages/MImageBody.tsx
index 332777be5e..d8cac8e28b 100644
--- a/src/components/views/messages/MImageBody.tsx
+++ b/src/components/views/messages/MImageBody.tsx
@@ -59,7 +59,7 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
     public static contextType = RoomContext;
     public declare context: React.ContextType<typeof RoomContext>;
 
-    private unmounted = true;
+    private unmounted = false;
     private image = createRef<HTMLImageElement>();
     private placeholder = createRef<HTMLDivElement>();
     private timeout?: number;
diff --git a/src/components/views/messages/MJitsiWidgetEvent.tsx b/src/components/views/messages/MJitsiWidgetEvent.tsx
index a547a78f94..bec4f56164 100644
--- a/src/components/views/messages/MJitsiWidgetEvent.tsx
+++ b/src/components/views/messages/MJitsiWidgetEvent.tsx
@@ -21,10 +21,6 @@ interface IProps {
 }
 
 export default class MJitsiWidgetEvent extends React.PureComponent<IProps> {
-    public constructor(props: IProps) {
-        super(props);
-    }
-
     public render(): React.ReactNode {
         const url = this.props.mxEvent.getContent()["url"];
         const prevUrl = this.props.mxEvent.getPrevContent()["url"];
diff --git a/src/components/views/messages/MLocationBody.tsx b/src/components/views/messages/MLocationBody.tsx
index 742587e0a7..b226476fa8 100644
--- a/src/components/views/messages/MLocationBody.tsx
+++ b/src/components/views/messages/MLocationBody.tsx
@@ -75,6 +75,10 @@ export default class MLocationBody extends React.Component<IBodyProps, IState> {
         this.context.on(ClientEvent.Sync, this.reconnectedListener);
     };
 
+    public componentDidMount(): void {
+        this.unmounted = false;
+    }
+
     public componentWillUnmount(): void {
         this.unmounted = true;
         this.context.off(ClientEvent.Sync, this.reconnectedListener);
diff --git a/src/components/views/rooms/AppsDrawer.tsx b/src/components/views/rooms/AppsDrawer.tsx
index 1d768cae35..c02bfe8cf2 100644
--- a/src/components/views/rooms/AppsDrawer.tsx
+++ b/src/components/views/rooms/AppsDrawer.tsx
@@ -68,11 +68,13 @@ export default class AppsDrawer extends React.Component<IProps, IState> {
         };
 
         this.resizer = this.createResizer();
-
-        this.props.resizeNotifier.on("isResizing", this.onIsResizing);
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
+
+        this.props.resizeNotifier.on("isResizing", this.onIsResizing);
+
         ScalarMessaging.startListening();
         WidgetLayoutStore.instance.on(WidgetLayoutStore.emissionForRoom(this.props.room), this.updateApps);
         this.dispatcherRef = dis.register(this.onAction);
diff --git a/src/components/views/rooms/BasicMessageComposer.tsx b/src/components/views/rooms/BasicMessageComposer.tsx
index 0add0c1027..5f033de238 100644
--- a/src/components/views/rooms/BasicMessageComposer.tsx
+++ b/src/components/views/rooms/BasicMessageComposer.tsx
@@ -128,10 +128,10 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
     private lastCaret!: DocumentOffset;
     private lastSelection: ReturnType<typeof cloneSelection> | null = null;
 
-    private readonly useMarkdownHandle: string;
-    private readonly emoticonSettingHandle: string;
-    private readonly shouldShowPillAvatarSettingHandle: string;
-    private readonly surroundWithHandle: string;
+    private useMarkdownHandle?: string;
+    private emoticonSettingHandle?: string;
+    private shouldShowPillAvatarSettingHandle?: string;
+    private surroundWithHandle?: string;
     private readonly historyManager = new HistoryManager();
 
     public constructor(props: IProps) {
@@ -145,28 +145,7 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
 
         const ua = navigator.userAgent.toLowerCase();
         this.isSafari = ua.includes("safari/") && !ua.includes("chrome/");
-
-        this.useMarkdownHandle = SettingsStore.watchSetting(
-            "MessageComposerInput.useMarkdown",
-            null,
-            this.configureUseMarkdown,
-        );
-        this.emoticonSettingHandle = SettingsStore.watchSetting(
-            "MessageComposerInput.autoReplaceEmoji",
-            null,
-            this.configureEmoticonAutoReplace,
-        );
         this.configureEmoticonAutoReplace();
-        this.shouldShowPillAvatarSettingHandle = SettingsStore.watchSetting(
-            "Pill.shouldShowPillAvatar",
-            null,
-            this.configureShouldShowPillAvatar,
-        );
-        this.surroundWithHandle = SettingsStore.watchSetting(
-            "MessageComposerInput.surroundWith",
-            null,
-            this.surroundWithSettingChanged,
-        );
     }
 
     public componentDidUpdate(prevProps: IProps): void {
@@ -737,6 +716,27 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
     }
 
     public componentDidMount(): void {
+        this.useMarkdownHandle = SettingsStore.watchSetting(
+            "MessageComposerInput.useMarkdown",
+            null,
+            this.configureUseMarkdown,
+        );
+        this.emoticonSettingHandle = SettingsStore.watchSetting(
+            "MessageComposerInput.autoReplaceEmoji",
+            null,
+            this.configureEmoticonAutoReplace,
+        );
+        this.shouldShowPillAvatarSettingHandle = SettingsStore.watchSetting(
+            "Pill.shouldShowPillAvatar",
+            null,
+            this.configureShouldShowPillAvatar,
+        );
+        this.surroundWithHandle = SettingsStore.watchSetting(
+            "MessageComposerInput.surroundWith",
+            null,
+            this.surroundWithSettingChanged,
+        );
+
         const model = this.props.model;
         model.setUpdateCallback(this.updateEditorState);
         const partCreator = model.partCreator;
diff --git a/src/components/views/rooms/EditMessageComposer.tsx b/src/components/views/rooms/EditMessageComposer.tsx
index 06f189df59..d62a451b8b 100644
--- a/src/components/views/rooms/EditMessageComposer.tsx
+++ b/src/components/views/rooms/EditMessageComposer.tsx
@@ -124,7 +124,7 @@ class EditMessageComposer extends React.Component<IEditMessageComposerProps, ISt
     public declare context: React.ContextType<typeof RoomContext>;
 
     private readonly editorRef = createRef<BasicMessageComposer>();
-    private readonly dispatcherRef: string;
+    private dispatcherRef?: string;
     private readonly replyToEvent?: MatrixEvent;
     private model!: EditorModel;
 
@@ -140,7 +140,9 @@ class EditMessageComposer extends React.Component<IEditMessageComposerProps, ISt
         this.state = {
             saveDisabled: !isRestored || !this.isContentModified(editContent["m.new_content"]!),
         };
+    }
 
+    public componentDidMount(): void {
         window.addEventListener("beforeunload", this.saveStoredEditorState);
         this.dispatcherRef = dis.register(this.onAction);
     }
diff --git a/src/components/views/rooms/EventTile.tsx b/src/components/views/rooms/EventTile.tsx
index eca61f7d22..0b600275ef 100644
--- a/src/components/views/rooms/EventTile.tsx
+++ b/src/components/views/rooms/EventTile.tsx
@@ -386,6 +386,7 @@ export class UnwrappedEventTile extends React.Component<EventTileProps, IState>
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
         this.suppressReadReceiptAnimation = false;
         const client = MatrixClientPeg.safeGet();
         if (!this.props.forExport) {
diff --git a/src/components/views/rooms/MemberList.tsx b/src/components/views/rooms/MemberList.tsx
index 993a2ba1f1..e503ce2363 100644
--- a/src/components/views/rooms/MemberList.tsx
+++ b/src/components/views/rooms/MemberList.tsx
@@ -72,7 +72,7 @@ interface IState {
 
 export default class MemberList extends React.Component<IProps, IState> {
     private readonly showPresence: boolean;
-    private mounted = false;
+    private unmounted = false;
 
     public static contextType = SDKContext;
     public declare context: React.ContextType<typeof SDKContext>;
@@ -82,8 +82,6 @@ export default class MemberList extends React.Component<IProps, IState> {
         super(props, context);
         this.state = this.getMembersState([], []);
         this.showPresence = context?.memberListStore.isPresenceEnabled() ?? true;
-        this.mounted = true;
-        this.listenForMembersChanges();
     }
 
     private listenForMembersChanges(): void {
@@ -102,11 +100,13 @@ export default class MemberList extends React.Component<IProps, IState> {
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
+        this.listenForMembersChanges();
         this.updateListNow(true);
     }
 
     public componentWillUnmount(): void {
-        this.mounted = false;
+        this.unmounted = true;
         const cli = MatrixClientPeg.get();
         if (cli) {
             cli.removeListener(RoomStateEvent.Update, this.onRoomStateUpdate);
@@ -205,7 +205,7 @@ export default class MemberList extends React.Component<IProps, IState> {
 
     // XXX: exported for tests
     public async updateListNow(showLoadingSpinner?: boolean): Promise<void> {
-        if (!this.mounted) {
+        if (this.unmounted) {
             return;
         }
         if (showLoadingSpinner) {
@@ -215,7 +215,7 @@ export default class MemberList extends React.Component<IProps, IState> {
             this.props.roomId,
             this.props.searchQuery,
         );
-        if (!this.mounted) {
+        if (this.unmounted) {
             return;
         }
         this.setState({
diff --git a/src/components/views/rooms/MessageComposer.tsx b/src/components/views/rooms/MessageComposer.tsx
index c8d1573ebc..69139fae5b 100644
--- a/src/components/views/rooms/MessageComposer.tsx
+++ b/src/components/views/rooms/MessageComposer.tsx
@@ -134,9 +134,6 @@ export class MessageComposer extends React.Component<IProps, IState> {
         super(props, context);
         this.context = context; // otherwise React will only set it prior to render due to type def above
 
-        VoiceRecordingStore.instance.on(UPDATE_EVENT, this.onVoiceStoreUpdate);
-
-        window.addEventListener("beforeunload", this.saveWysiwygEditorState);
         const isWysiwygLabEnabled = SettingsStore.getValue<boolean>("feature_wysiwyg_composer");
         let isRichTextEnabled = true;
         let initialComposerContent = "";
@@ -145,13 +142,6 @@ export class MessageComposer extends React.Component<IProps, IState> {
             if (wysiwygState) {
                 isRichTextEnabled = wysiwygState.isRichText;
                 initialComposerContent = wysiwygState.content;
-                if (wysiwygState.replyEventId) {
-                    dis.dispatch({
-                        action: "reply_to_event",
-                        event: this.props.room.findEventById(wysiwygState.replyEventId),
-                        context: this.context.timelineRenderingType,
-                    });
-                }
             }
         }
 
@@ -171,11 +161,6 @@ export class MessageComposer extends React.Component<IProps, IState> {
         };
 
         this.instanceId = instanceCount++;
-
-        SettingsStore.monitorSetting("MessageComposerInput.showStickersButton", null);
-        SettingsStore.monitorSetting("MessageComposerInput.showPollsButton", null);
-        SettingsStore.monitorSetting(Features.VoiceBroadcast, null);
-        SettingsStore.monitorSetting("feature_wysiwyg_composer", null);
     }
 
     private get editorStateKey(): string {
@@ -248,6 +233,25 @@ export class MessageComposer extends React.Component<IProps, IState> {
     }
 
     public componentDidMount(): void {
+        VoiceRecordingStore.instance.on(UPDATE_EVENT, this.onVoiceStoreUpdate);
+
+        window.addEventListener("beforeunload", this.saveWysiwygEditorState);
+        if (this.state.isWysiwygLabEnabled) {
+            const wysiwygState = this.restoreWysiwygEditorState();
+            if (wysiwygState?.replyEventId) {
+                dis.dispatch({
+                    action: "reply_to_event",
+                    event: this.props.room.findEventById(wysiwygState.replyEventId),
+                    context: this.context.timelineRenderingType,
+                });
+            }
+        }
+
+        SettingsStore.monitorSetting("MessageComposerInput.showStickersButton", null);
+        SettingsStore.monitorSetting("MessageComposerInput.showPollsButton", null);
+        SettingsStore.monitorSetting(Features.VoiceBroadcast, null);
+        SettingsStore.monitorSetting("feature_wysiwyg_composer", null);
+
         this.dispatcherRef = dis.register(this.onAction);
         this.waitForOwnMember();
         UIStore.instance.trackElementDimensions(`MessageComposer${this.instanceId}`, this.ref.current!);
diff --git a/src/components/views/rooms/NotificationBadge.tsx b/src/components/views/rooms/NotificationBadge.tsx
index c4cc418db4..6825ea8e43 100644
--- a/src/components/views/rooms/NotificationBadge.tsx
+++ b/src/components/views/rooms/NotificationBadge.tsx
@@ -44,15 +44,23 @@ interface IState {
 }
 
 export default class NotificationBadge extends React.PureComponent<XOR<IProps, IClickableProps>, IState> {
-    private countWatcherRef: string;
+    private countWatcherRef?: string;
 
     public constructor(props: IProps) {
         super(props);
-        this.props.notification.on(NotificationStateEvents.Update, this.onNotificationUpdate);
 
         this.state = {
             showCounts: SettingsStore.getValue("Notifications.alwaysShowBadgeCounts", this.roomId),
         };
+    }
+
+    private get roomId(): string | null {
+        // We should convert this to null for safety with the SettingsStore
+        return this.props.roomId || null;
+    }
+
+    public componentDidMount(): void {
+        this.props.notification.on(NotificationStateEvents.Update, this.onNotificationUpdate);
 
         this.countWatcherRef = SettingsStore.watchSetting(
             "Notifications.alwaysShowBadgeCounts",
@@ -61,11 +69,6 @@ export default class NotificationBadge extends React.PureComponent<XOR<IProps, I
         );
     }
 
-    private get roomId(): string | null {
-        // We should convert this to null for safety with the SettingsStore
-        return this.props.roomId || null;
-    }
-
     public componentWillUnmount(): void {
         SettingsStore.unwatchSetting(this.countWatcherRef);
         this.props.notification.off(NotificationStateEvents.Update, this.onNotificationUpdate);
diff --git a/src/components/views/rooms/RoomBreadcrumbs.tsx b/src/components/views/rooms/RoomBreadcrumbs.tsx
index 5de4687cb9..bb787d509a 100644
--- a/src/components/views/rooms/RoomBreadcrumbs.tsx
+++ b/src/components/views/rooms/RoomBreadcrumbs.tsx
@@ -60,7 +60,7 @@ const RoomBreadcrumbTile: React.FC<{ room: Room; onClick: (ev: ButtonEvent) => v
 };
 
 export default class RoomBreadcrumbs extends React.PureComponent<IProps, IState> {
-    private isMounted = true;
+    private unmounted = false;
     private toolbar = createRef<HTMLDivElement>();
 
     public constructor(props: IProps) {
@@ -70,17 +70,20 @@ export default class RoomBreadcrumbs extends React.PureComponent<IProps, IState>
             doAnimation: true, // technically we want animation on mount, but it won't be perfect
             skipFirst: false, // render the thing, as boring as it is
         };
+    }
 
+    public componentDidMount(): void {
+        this.unmounted = false;
         BreadcrumbsStore.instance.on(UPDATE_EVENT, this.onBreadcrumbsUpdate);
     }
 
     public componentWillUnmount(): void {
-        this.isMounted = false;
+        this.unmounted = true;
         BreadcrumbsStore.instance.off(UPDATE_EVENT, this.onBreadcrumbsUpdate);
     }
 
     private onBreadcrumbsUpdate = (): void => {
-        if (!this.isMounted) return;
+        if (this.unmounted) return;
 
         // We need to trick the CSSTransition component into updating, which means we need to
         // tell it to not animate, then to animate a moment later. This causes two updates
diff --git a/src/components/views/rooms/RoomTile.tsx b/src/components/views/rooms/RoomTile.tsx
index de14808f33..8351c176ff 100644
--- a/src/components/views/rooms/RoomTile.tsx
+++ b/src/components/views/rooms/RoomTile.tsx
@@ -94,7 +94,6 @@ export class RoomTile extends React.PureComponent<ClassProps, State> {
             // generatePreview() will return nothing if the user has previews disabled
             messagePreview: null,
         };
-        this.generatePreview();
 
         this.notificationState = RoomNotificationStateStore.instance.getRoomState(this.props.room);
         this.roomProps = EchoChamber.forRoom(this.props.room);
@@ -147,6 +146,8 @@ export class RoomTile extends React.PureComponent<ClassProps, State> {
     }
 
     public componentDidMount(): void {
+        this.generatePreview();
+
         // when we're first rendered (or our sublist is expanded) make sure we are visible if we're active
         if (this.state.selected) {
             this.scrollIntoView();
diff --git a/src/components/views/rooms/SendMessageComposer.tsx b/src/components/views/rooms/SendMessageComposer.tsx
index 776963eb33..a12a09dcb7 100644
--- a/src/components/views/rooms/SendMessageComposer.tsx
+++ b/src/components/views/rooms/SendMessageComposer.tsx
@@ -255,7 +255,7 @@ export class SendMessageComposer extends React.Component<ISendMessageComposerPro
     private readonly editorRef = createRef<BasicMessageComposer>();
     private model: EditorModel;
     private currentlyComposedEditorState: SerializedPart[] | null = null;
-    private dispatcherRef: string;
+    private dispatcherRef?: string;
     private sendHistoryManager: SendHistoryManager;
 
     public static defaultProps = {
@@ -275,15 +275,17 @@ export class SendMessageComposer extends React.Component<ISendMessageComposerPro
             );
         }
 
-        window.addEventListener("beforeunload", this.saveStoredEditorState);
-
         const partCreator = new CommandPartCreator(this.props.room, this.props.mxClient);
         const parts = this.restoreStoredEditorState(partCreator) || [];
         this.model = new EditorModel(parts, partCreator);
-        this.dispatcherRef = dis.register(this.onAction);
         this.sendHistoryManager = new SendHistoryManager(this.props.room.roomId, "mx_cider_history_");
     }
 
+    public componentDidMount(): void {
+        window.addEventListener("beforeunload", this.saveStoredEditorState);
+        this.dispatcherRef = dis.register(this.onAction);
+    }
+
     public componentDidUpdate(prevProps: ISendMessageComposerProps): void {
         const replyingToThread = this.props.relation?.key === THREAD_RELATION_TYPE.name;
         const differentEventTarget = this.props.relation?.event_id !== prevProps.relation?.event_id;
diff --git a/src/components/views/settings/CrossSigningPanel.tsx b/src/components/views/settings/CrossSigningPanel.tsx
index 6d00e182e8..a91238848e 100644
--- a/src/components/views/settings/CrossSigningPanel.tsx
+++ b/src/components/views/settings/CrossSigningPanel.tsx
@@ -45,6 +45,7 @@ export default class CrossSigningPanel extends React.PureComponent<{}, IState> {
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
         const cli = MatrixClientPeg.safeGet();
         cli.on(ClientEvent.AccountData, this.onAccountData);
         cli.on(CryptoEvent.UserTrustStatusChanged, this.onStatusChanged);
diff --git a/src/components/views/settings/CryptographyPanel.tsx b/src/components/views/settings/CryptographyPanel.tsx
index 08917d215c..ae0436a9e5 100644
--- a/src/components/views/settings/CryptographyPanel.tsx
+++ b/src/components/views/settings/CryptographyPanel.tsx
@@ -11,7 +11,6 @@ import { logger } from "matrix-js-sdk/src/logger";
 
 import type ExportE2eKeysDialog from "../../../async-components/views/dialogs/security/ExportE2eKeysDialog";
 import type ImportE2eKeysDialog from "../../../async-components/views/dialogs/security/ImportE2eKeysDialog";
-import { MatrixClientPeg } from "../../../MatrixClientPeg";
 import { _t } from "../../../languageHandler";
 import Modal from "../../../Modal";
 import AccessibleButton from "../elements/AccessibleButton";
@@ -20,6 +19,7 @@ import SettingsStore from "../../../settings/SettingsStore";
 import SettingsFlag from "../elements/SettingsFlag";
 import { SettingLevel } from "../../../settings/SettingLevel";
 import SettingsSubsection, { SettingsSubsectionText } from "./shared/SettingsSubsection";
+import MatrixClientContext from "../../../contexts/MatrixClientContext";
 
 interface IProps {}
 
@@ -33,17 +33,24 @@ interface IState {
 }
 
 export default class CryptographyPanel extends React.Component<IProps, IState> {
-    public constructor(props: IProps) {
+    public static contextType = MatrixClientContext;
+    public declare context: React.ContextType<typeof MatrixClientContext>;
+
+    public constructor(props: IProps, context: React.ContextType<typeof MatrixClientContext>) {
         super(props);
 
-        const client = MatrixClientPeg.safeGet();
-        const crypto = client.getCrypto();
-        if (!crypto) {
+        if (!context.getCrypto()) {
             this.state = { deviceIdentityKey: null };
         } else {
             this.state = { deviceIdentityKey: undefined };
-            crypto
-                .getOwnDeviceKeys()
+        }
+    }
+
+    public componentDidMount(): void {
+        if (this.state.deviceIdentityKey === undefined) {
+            this.context
+                .getCrypto()
+                ?.getOwnDeviceKeys()
                 .then((keys) => {
                     this.setState({ deviceIdentityKey: keys.ed25519 });
                 })
@@ -55,7 +62,7 @@ export default class CryptographyPanel extends React.Component<IProps, IState> {
     }
 
     public render(): React.ReactNode {
-        const client = MatrixClientPeg.safeGet();
+        const client = this.context;
         const deviceId = client.deviceId;
         let identityKey = this.state.deviceIdentityKey;
         if (identityKey === undefined) {
@@ -126,7 +133,7 @@ export default class CryptographyPanel extends React.Component<IProps, IState> {
             import("../../../async-components/views/dialogs/security/ExportE2eKeysDialog") as unknown as Promise<
                 typeof ExportE2eKeysDialog
             >,
-            { matrixClient: MatrixClientPeg.safeGet() },
+            { matrixClient: this.context },
         );
     };
 
@@ -135,12 +142,12 @@ export default class CryptographyPanel extends React.Component<IProps, IState> {
             import("../../../async-components/views/dialogs/security/ImportE2eKeysDialog") as unknown as Promise<
                 typeof ImportE2eKeysDialog
             >,
-            { matrixClient: MatrixClientPeg.safeGet() },
+            { matrixClient: this.context },
         );
     };
 
     private updateBlacklistDevicesFlag = (checked: boolean): void => {
-        const crypto = MatrixClientPeg.safeGet().getCrypto();
+        const crypto = this.context.getCrypto();
         if (crypto) crypto.globalBlacklistUnverifiedDevices = checked;
     };
 }
diff --git a/src/components/views/settings/FontScalingPanel.tsx b/src/components/views/settings/FontScalingPanel.tsx
index f6dedb3ffb..b7f7c64a3b 100644
--- a/src/components/views/settings/FontScalingPanel.tsx
+++ b/src/components/views/settings/FontScalingPanel.tsx
@@ -55,6 +55,7 @@ export default class FontScalingPanel extends React.Component<IProps, IState> {
     }
 
     public async componentDidMount(): Promise<void> {
+        this.unmounted = false;
         // Fetch the current user profile for the message preview
         const client = MatrixClientPeg.safeGet();
         const userId = client.getSafeUserId();
diff --git a/src/components/views/settings/Notifications.tsx b/src/components/views/settings/Notifications.tsx
index 78660d4f9d..6890c7b5d3 100644
--- a/src/components/views/settings/Notifications.tsx
+++ b/src/components/views/settings/Notifications.tsx
@@ -206,7 +206,7 @@ const NotificationActivitySettings = (): JSX.Element => {
  * The old, deprecated notifications tab view, only displayed if the user has the labs flag disabled.
  */
 export default class Notifications extends React.PureComponent<IProps, IState> {
-    private settingWatchers: string[];
+    private settingWatchers: string[] = [];
 
     public constructor(props: IProps) {
         super(props);
@@ -220,7 +220,17 @@ export default class Notifications extends React.PureComponent<IProps, IState> {
             clearingNotifications: false,
             ruleIdsWithError: {},
         };
+    }
 
+    private get isInhibited(): boolean {
+        // Caution: The master rule's enabled state is inverted from expectation. When
+        // the master rule is *enabled* it means all other rules are *disabled* (or
+        // inhibited). Conversely, when the master rule is *disabled* then all other rules
+        // are *enabled* (or operate fine).
+        return !!this.state.masterPushRule?.enabled;
+    }
+
+    public componentDidMount(): void {
         this.settingWatchers = [
             SettingsStore.watchSetting("notificationsEnabled", null, (...[, , , , value]) =>
                 this.setState({ desktopNotifications: value as boolean }),
@@ -235,17 +245,7 @@ export default class Notifications extends React.PureComponent<IProps, IState> {
                 this.setState({ audioNotifications: value as boolean }),
             ),
         ];
-    }
 
-    private get isInhibited(): boolean {
-        // Caution: The master rule's enabled state is inverted from expectation. When
-        // the master rule is *enabled* it means all other rules are *disabled* (or
-        // inhibited). Conversely, when the master rule is *disabled* then all other rules
-        // are *enabled* (or operate fine).
-        return !!this.state.masterPushRule?.enabled;
-    }
-
-    public componentDidMount(): void {
         // noinspection JSIgnoredPromiseFromCall
         this.refreshFromServer();
         this.refreshFromAccountData();
diff --git a/src/components/views/settings/SecureBackupPanel.tsx b/src/components/views/settings/SecureBackupPanel.tsx
index dac7425e3c..6a855c8ea8 100644
--- a/src/components/views/settings/SecureBackupPanel.tsx
+++ b/src/components/views/settings/SecureBackupPanel.tsx
@@ -83,6 +83,7 @@ export default class SecureBackupPanel extends React.PureComponent<{}, IState> {
     }
 
     public componentDidMount(): void {
+        this.unmounted = false;
         this.loadBackupStatus();
 
         MatrixClientPeg.safeGet().on(CryptoEvent.KeyBackupStatus, this.onKeyBackupStatus);
diff --git a/src/components/views/settings/tabs/room/AdvancedRoomSettingsTab.tsx b/src/components/views/settings/tabs/room/AdvancedRoomSettingsTab.tsx
index c32ac5150b..337cead3a3 100644
--- a/src/components/views/settings/tabs/room/AdvancedRoomSettingsTab.tsx
+++ b/src/components/views/settings/tabs/room/AdvancedRoomSettingsTab.tsx
@@ -53,9 +53,11 @@ export default class AdvancedRoomSettingsTab extends React.Component<IProps, ISt
     public constructor(props: IProps) {
         super(props);
 
-        const msc3946ProcessDynamicPredecessor = SettingsStore.getValue("feature_dynamic_room_predecessors");
-
         this.state = {};
+    }
+
+    public componentDidMount(): void {
+        const msc3946ProcessDynamicPredecessor = SettingsStore.getValue("feature_dynamic_room_predecessors");
 
         // we handle lack of this object gracefully later, so don't worry about it failing here.
         const room = this.props.room;
diff --git a/src/components/views/spaces/SpaceTreeLevel.tsx b/src/components/views/spaces/SpaceTreeLevel.tsx
index 1cb6006228..c9498b8dd9 100644
--- a/src/components/views/spaces/SpaceTreeLevel.tsx
+++ b/src/components/views/spaces/SpaceTreeLevel.tsx
@@ -205,7 +205,9 @@ export class SpaceItem extends React.PureComponent<IItemProps, IItemState> {
             collapsed,
             childSpaces: this.childSpaces,
         };
+    }
 
+    public componentDidMount(): void {
         SpaceStore.instance.on(this.props.space.roomId, this.onSpaceUpdate);
         this.props.space.on(RoomEvent.Name, this.onRoomNameChange);
     }
diff --git a/src/components/views/voip/LegacyCallView.tsx b/src/components/views/voip/LegacyCallView.tsx
index 124d078782..aba3d60743 100644
--- a/src/components/views/voip/LegacyCallView.tsx
+++ b/src/components/views/voip/LegacyCallView.tsx
@@ -110,11 +110,10 @@ export default class LegacyCallView extends React.Component<IProps, IState> {
             sidebarFeeds: sidebar,
             sidebarShown: true,
         };
-
-        this.updateCallListeners(null, this.props.call);
     }
 
     public componentDidMount(): void {
+        this.updateCallListeners(null, this.props.call);
         this.dispatcherRef = dis.register(this.onAction);
         document.addEventListener("keydown", this.onNativeKeyDown);
     }
diff --git a/test/unit-tests/components/views/settings/CryptographyPanel-test.tsx b/test/unit-tests/components/views/settings/CryptographyPanel-test.tsx
index ce506461ee..0b699c1383 100644
--- a/test/unit-tests/components/views/settings/CryptographyPanel-test.tsx
+++ b/test/unit-tests/components/views/settings/CryptographyPanel-test.tsx
@@ -14,6 +14,7 @@ import { mocked } from "jest-mock";
 import { MatrixClientPeg } from "../../../../../src/MatrixClientPeg";
 import * as TestUtils from "../../../../test-utils";
 import CryptographyPanel from "../../../../../src/components/views/settings/CryptographyPanel";
+import { withClientContextRenderOptions } from "../../../../test-utils";
 
 describe("CryptographyPanel", () => {
     it("shows the session ID and key", async () => {
@@ -28,7 +29,7 @@ describe("CryptographyPanel", () => {
         mocked(client.getCrypto()!.getOwnDeviceKeys).mockResolvedValue({ ed25519: sessionKey, curve25519: "1234" });
 
         // When we render the CryptographyPanel
-        const rendered = render(<CryptographyPanel />);
+        const rendered = render(<CryptographyPanel />, withClientContextRenderOptions(client));
 
         // Then it displays info about the user's session
         const codes = rendered.container.querySelectorAll("code");
@@ -52,7 +53,7 @@ describe("CryptographyPanel", () => {
         mocked(client.getCrypto()!.getOwnDeviceKeys).mockRejectedValue(new Error("bleh"));
 
         // When we render the CryptographyPanel
-        const rendered = render(<CryptographyPanel />);
+        const rendered = render(<CryptographyPanel />, withClientContextRenderOptions(client));
 
         // Then it displays info about the user's session
         const codes = rendered.container.querySelectorAll("code");