diff --git a/js/nostr/adapters/nip07Adapter.js b/js/nostr/adapters/nip07Adapter.js
index dbe0f564..37bf5068 100644
--- a/js/nostr/adapters/nip07Adapter.js
+++ b/js/nostr/adapters/nip07Adapter.js
@@ -42,7 +42,7 @@ function resolveNip44Module(extension) {
   return nip44;
 }
 
-export async function createNip07Adapter(initialExtension) {
+export async function createNip07Adapter(initialExtension, { preloadedPubkey } = {}) {
   const getExtension = () => {
     if (typeof window !== "undefined" && window.nostr) {
       return window.nostr;
@@ -86,9 +86,10 @@ export async function createNip07Adapter(initialExtension) {
   };
 
   const pubkey =
-    typeof bootstrapExtension.getPublicKey === "function"
+    preloadedPubkey ||
+    (typeof bootstrapExtension.getPublicKey === "function"
       ? normalizeActorKey(await getPublicKey())
-      : "";
+      : "");
 
   // Wrapper builders to ensure dynamic lookup at call time
   const createNip04Encrypt = () => (pubkey, plaintext, options = {}) => {
diff --git a/js/nostr/client.js b/js/nostr/client.js
index 9c473f41..893edabb 100644
--- a/js/nostr/client.js
+++ b/js/nostr/client.js
@@ -3053,11 +3053,19 @@ export class NostrClient {
       return existingSigner;
     }
 
+    // Optimization: Check if a signer was registered while we were waiting for the extension call
+    const raceWinner = resolveActiveSigner(extensionPubkey || normalizedPubkey);
+    if (raceWinner && typeof raceWinner.signEvent === "function") {
+      return raceWinner;
+    }
+
     if (typeof extension.signEvent !== "function") {
       return existingSigner;
     }
 
-    const adapter = await createNip07Adapter(extension);
+    const adapter = await createNip07Adapter(extension, {
+      preloadedPubkey: extensionPubkey,
+    });
     if (extensionPubkey) {
       adapter.pubkey = extensionPubkey;
     }
diff --git a/js/subscriptions.js b/js/subscriptions.js
index 6a61cc8d..bccb873e 100644
--- a/js/subscriptions.js
+++ b/js/subscriptions.js
@@ -491,7 +491,7 @@ class SubscriptionsManager {
         pubkey: normalizedUserPubkey,
         dTag: SUBSCRIPTION_LIST_IDENTIFIER,
         relayUrls,
-        since: shouldForceFullFetch ? 0 : undefined,
+        since: shouldForceFullFetch ? 0 : (cachedSnapshot.createdAt || 0),
         timeoutMs: 12000,
       });
 
@@ -514,7 +514,7 @@ class SubscriptionsManager {
           pubkey: normalizedSessionActorPubkey,
           dTag: SUBSCRIPTION_LIST_IDENTIFIER,
           relayUrls,
-          since: shouldForceSessionFetch ? 0 : undefined,
+          since: shouldForceSessionFetch ? 0 : (sessionCachedSnapshot.createdAt || 0),
           timeoutMs: 12000,
         });
         if (sessionEvents.length) {
diff --git a/js/userBlocks.js b/js/userBlocks.js
index 0f4724f0..4601dee6 100644
--- a/js/userBlocks.js
+++ b/js/userBlocks.js
@@ -908,11 +908,14 @@ class UserBlockListManager {
     }
     this.ensureBlockListSubscription(normalized, relays);
 
-    const localBlocks = this._loadLocal(normalized);
-    const hasLocalData = !!localBlocks;
+    const localData = this._loadLocal(normalized);
+    const hasLocalData = !!localData;
 
-    if (localBlocks) {
-      this.blockedPubkeys = localBlocks;
+    if (localData) {
+      this.blockedPubkeys = localData.blockedPubkeys;
+      if (Number.isFinite(localData.createdAt)) {
+        this.blockEventCreatedAt = localData.createdAt;
+      }
       this.loaded = true;
       this.emitter.emit(USER_BLOCK_EVENTS.CHANGE, {
         action: "sync",
@@ -1385,9 +1388,13 @@ class UserBlockListManager {
         }
       };
 
-      // If we don't have local data, we must ignore the sync metadata and force a full fetch (since: 0).
-      // Otherwise, we might miss data if the metadata store says we are up-to-date but the actual list is missing.
-      const fetchSince = hasLocalData ? undefined : 0;
+      // Anchor the fetch to the service's current state to prevent desync.
+      // If we have cached data, we ask for updates since that timestamp.
+      // If we have no data, we force a full fetch (since=0).
+      const fetchSince =
+        hasLocalData && Number.isFinite(this.blockEventCreatedAt)
+          ? this.blockEventCreatedAt
+          : 0;
 
       // Concurrent incremental fetch for both kinds
       const [muteEvents, blockEvents] = await Promise.all([
@@ -1437,7 +1444,15 @@ class UserBlockListManager {
     }
     const cached = profileCache.getProfileData(normalizedActorHex, "blocks");
     if (Array.isArray(cached)) {
-      return new Set(cached);
+      return { blockedPubkeys: new Set(cached), createdAt: null };
+    }
+    if (cached && typeof cached === "object") {
+      return {
+        blockedPubkeys: new Set(
+          Array.isArray(cached.blockedPubkeys) ? cached.blockedPubkeys : [],
+        ),
+        createdAt: Number.isFinite(cached.createdAt) ? cached.createdAt : null,
+      };
     }
     return null;
   }
@@ -1447,11 +1462,11 @@ class UserBlockListManager {
     if (!normalizedActorHex) {
       return;
     }
-    profileCache.setProfileData(
-      normalizedActorHex,
-      "blocks",
-      Array.from(this.blockedPubkeys),
-    );
+    profileCache.setProfileData(normalizedActorHex, "blocks", {
+      blockedPubkeys: Array.from(this.blockedPubkeys),
+      createdAt: this.blockEventCreatedAt,
+      version: 1,
+    });
   }
 
   _getSeedState(actorHex) {
diff --git a/tests/subscriptions-manager.test.mjs b/tests/subscriptions-manager.test.mjs
index 183eeb42..d325c089 100644
--- a/tests/subscriptions-manager.test.mjs
+++ b/tests/subscriptions-manager.test.mjs
@@ -1,3 +1,4 @@
+import "./test-helpers/setup-localstorage.mjs";
 import { test } from "node:test";
 import assert from "node:assert/strict";