diff --git a/src/lib/stores/backupStatus.ts b/src/lib/stores/backupStatus.ts
index 5071186..130e0f3 100644
--- a/src/lib/stores/backupStatus.ts
+++ b/src/lib/stores/backupStatus.ts
@@ -24,7 +24,19 @@ export function setBackupStatus(integrations: IntegrationSummary[]): void {
 	backupsNeedingReconnect.set(integrations.filter((i) => !i.enabled).map((i) => i.provider));
 }
 
-export async function refreshBackupStatus(): Promise<void> {
+let refreshInFlight: { generation: number; promise: Promise<void> } | null = null;
+
+export function refreshBackupStatus(): Promise<void> {
+	if (refreshInFlight?.generation === mutationGeneration) return refreshInFlight.promise;
+	const generation = mutationGeneration;
+	const promise = performRefresh().finally(() => {
+		if (refreshInFlight?.promise === promise) refreshInFlight = null;
+	});
+	refreshInFlight = { generation, promise };
+	return promise;
+}
+
+async function performRefresh(): Promise<void> {
 	if (typeof window === 'undefined' || !navigator.onLine) return;
 	const sequence = ++refreshSequence;
 	const generation = mutationGeneration;
diff --git a/src/lib/stores/offlineSync.ts b/src/lib/stores/offlineSync.ts
index a6fa049..271a3b9 100644
--- a/src/lib/stores/offlineSync.ts
+++ b/src/lib/stores/offlineSync.ts
@@ -1,3 +1,4 @@
+import { afterCriticalPageWork } from '$lib/utils/criticalPageWork';
 import { writable } from 'svelte/store';
 import { PUBLIC_USE_LOCAL_POKEMON_SPRITE_FOLDER } from '$env/static/public';
 import type { OfflineSnapshot } from '$lib/models/OfflineSnapshot';
@@ -246,15 +247,19 @@ export function startOfflineSync(getUserId: () => string | null): () => void {
 		}, 1_000);
 	};
 	// Explicit requests (edits, Retry, a new sign-in) and reconnecting always fetch a new copy.
-	const schedule = () => scheduleSync(false);
+	const schedule = () => {
+		cancelStartup();
+		scheduleSync(false);
+	};
 
 	// Best effort: ask the browser not to evict the offline artwork cache under storage pressure.
 	void navigator.storage?.persist?.().catch(() => undefined);
 	window.addEventListener(SYNC_EVENT, schedule);
 	window.addEventListener('online', schedule);
-	scheduleSync(true);
+	const cancelStartup = afterCriticalPageWork(() => scheduleSync(true));
 	return () => {
 		stopped = true;
+		cancelStartup();
 		if (timer !== null) window.clearTimeout(timer);
 		window.removeEventListener(SYNC_EVENT, schedule);
 		window.removeEventListener('online', schedule);
diff --git a/src/routes/+layout.svelte b/src/routes/+layout.svelte
index a0e9677..d4217fa 100644
--- a/src/routes/+layout.svelte
+++ b/src/routes/+layout.svelte
@@ -2,6 +2,7 @@
 	// The only app stylesheet: Vite bundles, minifies and content-hashes it so it is cached for good.
 	// static/output.css is built separately for the credential-free offline.html page only.
 	import '../app.css';
+	import { afterCriticalPageWork } from '$lib/utils/criticalPageWork';
 	import { onDestroy, onMount } from 'svelte';
 	import { user } from '$lib/stores/user.js';
 	import { type User } from '@supabase/auth-js';
@@ -27,18 +28,21 @@
 	let { supabase } = data;
 	$: ({ supabase } = data);
 
-	let localUser = null as User | null;
+	let localUser: User | null = data.user ?? null;
+	let userStoreReady = false;
 	const unsubscribe = user.subscribe((value) => {
-		localUser = value;
+		if (userStoreReady) localUser = value;
 	});
 	onDestroy(unsubscribe);
 
 	let authSubscription: { unsubscribe: () => void } | null = null;
+	let cancelBackupStartup: (() => void) | null = null;
 	let stopOfflineSync: (() => void) | null = null;
 	let isOnline = true;
 	let signOutError = '';
 
 	onMount(() => {
+		userStoreReady = true;
 		isOnline = navigator.onLine;
 		const updateOnlineState = () => {
 			isOnline = navigator.onLine;
@@ -60,7 +64,9 @@
 		void getUser()
 			.then(async () => {
 				if (localUser) {
-					void refreshBackupStatus();
+					cancelBackupStartup = afterCriticalPageWork(() => {
+						if (localUser) void refreshBackupStatus();
+					});
 					await claimOfflineData(localUser.id);
 				}
 				stopOfflineSync = startOfflineSync(() => localUser?.id ?? null);
@@ -77,6 +83,8 @@
 				// SIGNED_IN also fires when a tab regains focus, so only a change of account fetches a new
 				// offline copy. Page loads and token refreshes reuse the saved one while it is fresh.
 				if (event === 'SIGNED_IN' && session.user.id !== previousUserId) {
+					cancelBackupStartup?.();
+					clearBackupStatus();
 					void claimOfflineData(session.user.id)
 						.then(requestOfflineSync)
 						.catch((error) => console.error('Unable to claim offline data', error));
@@ -96,6 +104,7 @@
 		return () => {
 			authSubscription?.unsubscribe();
 			stopOfflineSync?.();
+			cancelBackupStartup?.();
 			window.removeEventListener('online', updateOnlineState);
 			window.removeEventListener('offline', updateOnlineState);
 			for (const name of ['click', 'submit', 'input', 'change', 'keydown']) {
diff --git a/src/routes/+layout.ts b/src/routes/+layout.ts
index 72058fb..e3c7c6c 100644
--- a/src/routes/+layout.ts
+++ b/src/routes/+layout.ts
@@ -60,6 +60,7 @@ export const load: LayoutLoad = async ({ fetch, data, depends }) => {
 	return {
 		supabase,
 		session,
+		user: data.user,
 		recoveryIntent: !!session && (hashRecoveryCallback || recoveryExchangeSucceeded)
 	};
 };
diff --git a/tests/unit/backupStatus.test.ts b/tests/unit/backupStatus.test.ts
index 1161fc0..606380e 100644
--- a/tests/unit/backupStatus.test.ts
+++ b/tests/unit/backupStatus.test.ts
@@ -112,13 +112,25 @@ describe('refreshBackupStatus', () => {
 
 	const json = (body: unknown) => new Response(JSON.stringify(body));
 
-	it('ignores a response overtaken by a newer refresh', async () => {
+	it('coalesces concurrent refreshes for the same account state', async () => {
+		const slow = deferredResponse();
+		fetchMock.mockReturnValueOnce(slow.promise);
+		const first = refreshBackupStatus();
+		const second = refreshBackupStatus();
+		expect(second).toBe(first);
+		expect(fetchMock).toHaveBeenCalledTimes(1);
+		slow.resolve(json([]));
+		await Promise.all([first, second]);
+	});
+
+	it('ignores a response overtaken by a new account refresh', async () => {
 		const slow = deferredResponse();
 		fetchMock
 			.mockReturnValueOnce(slow.promise)
 			.mockResolvedValueOnce(json([{ provider: 'google_drive', enabled: true }]));
 
 		const first = refreshBackupStatus();
+		clearBackupStatus();
 		await refreshBackupStatus();
 		slow.resolve(json([{ provider: 'google_drive', enabled: false }]));
 		await first;