diff --git a/frontend-v2/src/app/event/activist-registry.ts b/frontend-v2/src/app/event/activist-registry.ts
index e950a8f2..bc82fa0b 100644
--- a/frontend-v2/src/app/event/activist-registry.ts
+++ b/frontend-v2/src/app/event/activist-registry.ts
@@ -15,9 +15,7 @@ export type ActivistRecord = {
  * Reads are synchronous (from memory) for fast autocomplete/filtering.
  * Writes are async and automatically persist to IndexedDB when storage is configured.
  *
- * @param storage - Optional IndexedDB storage for persistence.
- *                  When provided, enables automatic write-through caching.
- *                  When omitted, registry operates in memory-only mode.
+ * When storage is not configured, registry operates in memory-only mode.
  */
 export class ActivistRegistry {
   private activists: ActivistRecord[]
@@ -25,11 +23,10 @@ export class ActivistRegistry {
   private activistsById: Map<number, ActivistRecord>
   private storage?: ActivistStorage
 
-  constructor(storage?: ActivistStorage) {
+  constructor() {
     this.activists = []
     this.activistsByName = new Map()
     this.activistsById = new Map()
-    this.storage = storage
   }
 
   /**
@@ -48,24 +45,18 @@ export class ActivistRegistry {
   /**
    * Loads activists from IndexedDB storage into memory.
    * Call once after construction, before first use of the registry.
-   * @throws Error if storage is not configured
    */
-  async loadFromStorage(): Promise<void> {
-    if (!this.storage) {
-      throw new Error(
-        'Cannot load activists from storage: storage not configured.',
-      )
-    }
+  async loadFromStorage(storage: ActivistStorage): Promise<void> {
+    this.storage = storage
 
-    const stored = await this.storage.getAllActivists()
-    this.activists = stored
+    this.activists = await this.storage.getAllActivists()
     this.sortActivists()
-    this.activistsByName = new Map(stored.map((a) => [a.name, a]))
-    this.activistsById = new Map(stored.map((a) => [a.id, a]))
+    this.activistsByName = new Map(this.activists.map((a) => [a.name, a]))
+    this.activistsById = new Map(this.activists.map((a) => [a.id, a]))
   }
 
   /**
-   * Merges new activists with existing data, replacing duplicates by id.
+   * Merges new activists with existing data.
    * If storage is configured, persists updates to IndexedDB.
    */
   async mergeActivists(newActivists: ActivistRecord[]): Promise<void> {
@@ -79,27 +70,17 @@ export class ActivistRegistry {
       const existingIndex = indexById.get(activist.id) ?? -1
 
       if (existingIndex >= 0) {
-        // Update existing activist (handles renames properly)
-        const oldActivist = this.activists[existingIndex]
         this.activists[existingIndex] = activist
-
-        // Remove old name from index if name changed
-        if (oldActivist.name !== activist.name) {
-          this.activistsByName.delete(oldActivist.name)
-        }
       } else {
-        // Add new activist
         this.activists.push(activist)
         indexById.set(activist.id, this.activists.length - 1)
       }
 
-      // Update indexes
-      this.activistsByName.set(activist.name, activist)
       this.activistsById.set(activist.id, activist)
     }
 
-    // Re-sort after batch updates to maintain sort order
     this.sortActivists()
+    this.activistsByName = new Map(this.activists.map((a) => [a.name, a]))
 
     // Write through to storage if configured
     await this.storage?.saveActivists(newActivists)
@@ -116,14 +97,16 @@ export class ActivistRegistry {
 
     const idsToRemove = new Set(ids)
 
-    this.activists = this.activists.filter((activist) => {
+    const remainingActivists: ActivistRecord[] = []
+    for (const activist of this.activists) {
       if (idsToRemove.has(activist.id)) {
         this.activistsByName.delete(activist.name)
         this.activistsById.delete(activist.id)
-        return false
+        continue
       }
-      return true
-    })
+      remainingActivists.push(activist)
+    }
+    this.activists = remainingActivists
 
     // Write through to storage if configured
     await this.storage?.deleteActivistsByIds(ids)
diff --git a/frontend-v2/src/app/event/activist-storage.ts b/frontend-v2/src/app/event/activist-storage.ts
index 1322cb74..2b4fb43a 100644
--- a/frontend-v2/src/app/event/activist-storage.ts
+++ b/frontend-v2/src/app/event/activist-storage.ts
@@ -3,7 +3,7 @@
  * Provides caching and incremental sync capabilities.
  *
  * Why IndexedDB instead of localStorage:
- * - Data size: ~3MB currently, approaching localStorage's 5-10MB limit
+ * - Data size: ~3MB as of January 2026, approaching localStorage's 5-10MB limit
  * - Async operations: Avoid blocking main thread with large JSON parse/stringify
  * - Structured storage: Store by ID with built-in indexing
  */
@@ -121,7 +121,10 @@ export class ActivistStorage {
       const request =
         timestamp === null
           ? store.delete('lastSync')
-          : store.put({ lastSyncTime: timestamp }, 'lastSync')
+          : store.put(
+              { lastSyncTime: timestamp } satisfies SyncMetadata,
+              'lastSync',
+            )
 
       request.onsuccess = () => resolve()
       request.onerror = () => reject(request.error)
diff --git a/frontend-v2/src/app/event/useActivistRegistry.ts b/frontend-v2/src/app/event/useActivistRegistry.ts
index 07a3482a..bc8b6afa 100644
--- a/frontend-v2/src/app/event/useActivistRegistry.ts
+++ b/frontend-v2/src/app/event/useActivistRegistry.ts
@@ -15,7 +15,8 @@ import toast from 'react-hot-toast'
  */
 export function useActivistRegistry() {
   // Single registry instance with write-through storage to IndexedDB (if available)
-  const registryRef = useRef(new ActivistRegistry(activistStorage))
+  const registry = new ActivistRegistry()
+  const registryRef = useRef(registry)
   const [isStorageLoaded, setIsStorageLoaded] = useState(false)
   const [isServerLoaded, setIsServerLoaded] = useState(false)
 
@@ -33,7 +34,7 @@ export function useActivistRegistry() {
     }
 
     registryRef.current
-      .loadFromStorage()
+      .loadFromStorage(activistStorage)
       .then(() => {
         if (mounted) setIsStorageLoaded(true)
       })
@@ -131,9 +132,7 @@ export function useActivistRegistry() {
       }
 
       // Merge newer activists (registry handles both memory and storage)
-      if (activistsToUpdate.length > 0) {
-        await registryRef.current.mergeActivists(activistsToUpdate)
-      }
+      await registryRef.current.mergeActivists(activistsToUpdate)
 
       // Update last sync timestamp
       await registryRef.current.setLastSyncTime(new Date().toISOString())