diff --git a/src/routes/+layout.ts b/src/routes/+layout.ts
index f1b581af..1fa24771 100644
--- a/src/routes/+layout.ts
+++ b/src/routes/+layout.ts
@@ -140,13 +140,32 @@ export async function load({ fetch, params, parent, route, url }) {
                     site_domain_id: native_device_config.site_domain_id || native_device_config.site_domain_id_random,
                 };
                 
-                // Inject native device metadata into the location state
+                // Inject native device metadata into the location state with SAFE MERGE
                 if (native_device_config.native_device) {
-                    ae_loc_init['native_device'] = native_device_config.native_device;
+                    const incoming_dev = native_device_config.native_device;
+                    
+                    // 1. Recover existing user overrides from localStorage
+                    let existing_dev = {};
+                    try {
+                        const raw = localStorage.getItem('ae_loc');
+                        if (raw) existing_dev = JSON.parse(raw).native_device || {};
+                    } catch (e) {}
+
+                    // 2. Merge: Priority to EXISTING overrides for specific timers
+                    ae_loc_init['native_device'] = {
+                        ...incoming_dev,
+                        // Persist these specific user-controlled fields
+                        check_event_loop_period: (existing_dev as any).check_event_loop_period || incoming_dev.check_event_loop_period,
+                        check_event_device_loop_period: (existing_dev as any).check_event_device_loop_period || incoming_dev.check_event_device_loop_period,
+                        check_event_location_loop_period: (existing_dev as any).check_event_location_loop_period || incoming_dev.check_event_location_loop_period,
+                        check_event_session_loop_period: (existing_dev as any).check_event_session_loop_period || incoming_dev.check_event_session_loop_period,
+                        hash_prefix_length: (existing_dev as any).hash_prefix_length || incoming_dev.hash_prefix_length
+                    };
+
                     // Map specific operational paths
-                    ae_loc_init['local_file_cache_path'] = native_device_config.native_device.local_file_cache_path;
-                    ae_loc_init['host_file_temp_path'] = native_device_config.native_device.host_file_temp_path;
-                    ae_loc_init['recording_path'] = native_device_config.native_device.recording_path;
+                    ae_loc_init['local_file_cache_path'] = incoming_dev.local_file_cache_path;
+                    ae_loc_init['host_file_temp_path'] = incoming_dev.host_file_temp_path;
+                    ae_loc_init['recording_path'] = incoming_dev.recording_path;
                 }
 
                 // IMPORTANT: Update API settings with the native-authorized key if present
diff --git a/src/routes/events/[event_id]/(launcher)/launcher_background_sync.svelte b/src/routes/events/[event_id]/(launcher)/launcher_background_sync.svelte
index 4277bfaa..21b2cf9f 100644
--- a/src/routes/events/[event_id]/(launcher)/launcher_background_sync.svelte
+++ b/src/routes/events/[event_id]/(launcher)/launcher_background_sync.svelte
@@ -1,8 +1,7 @@
 <script lang="ts">
     /**
      * launcher_background_sync.svelte
-     * Exhaustive Background Pre-Caching Engine.
-     * Scans Sessions, Presentations, and Presenters to ensure 100% of room files are cached.
+     * Exhaustive Background Pre-Caching Engine with Loop Monitoring.
      */
     import { onMount, onDestroy } from 'svelte';
     import { ae_loc, ae_api } from '$lib/stores/ae_stores';
@@ -16,46 +15,59 @@
     let sync_results: Record<string, 'success' | 'error' | 'pending'> = $state({});
     let sync_stats = $state({ total: 0, cached: 0, missing: 0 });
     
-    let main_sync_interval: any = null;
+    // Loop Timings (Visible in UI)
+    let loop_info = $state({
+        event: 90000,
+        device: 60000,
+        location: 30000,
+        session: 10000
+    });
+
+    // Timer Handles
+    let timer__event: any = null;
+    let timer__device: any = null;
+    let timer__location: any = null;
+    let timer__session: any = null;
+
     let is_syncing = false;
+    let show_monitor = $state(false);
 
     onMount(() => {
         if (!$ae_loc.is_native) return;
 
-        if (log_lvl) console.log('Sync: Starting exhaustive background caching engine.');
-
-        // Setup persistent loop (Check every 10s for new data/missing files)
-        const sync_period = 10000; 
+        const dev = $ae_loc.native_device || {};
         
-        main_sync_interval = setInterval(() => {
-            if (!is_syncing) {
-                run_sync_cycle();
-            }
-        }, sync_period);
+        // Load timings from device config
+        loop_info.event = dev.check_event_loop_period || 90000;
+        loop_info.device = dev.check_event_device_loop_period || 60000;
+        loop_info.location = dev.check_event_location_loop_period || 30000;
+        loop_info.session = dev.check_event_session_loop_period || 10000;
+
+        timer__event = setInterval(() => run_sync_cycle(), loop_info.event);
+        timer__device = setInterval(() => { /* TODO: Heartbeat */ }, loop_info.device);
+        timer__location = setInterval(() => { /* TODO: Refresh Loc */ }, loop_info.location);
+        timer__session = setInterval(() => run_sync_cycle(), loop_info.session);
 
         // Immediate first run
         run_sync_cycle();
     });
 
     onDestroy(() => {
-        if (main_sync_interval) clearInterval(main_sync_interval);
+        if (timer__event) clearInterval(timer__event);
+        if (timer__device) clearInterval(timer__device);
+        if (timer__location) clearInterval(timer__location);
+        if (timer__session) clearInterval(timer__session);
     });
 
-    /**
-     * Primary Sync Cycle
-     * Recursively identifies ALL files in the room hierarchy.
-     */
     async function run_sync_cycle() {
         const location_id = $events_slct.event_location_id;
         const cache_root = $ae_loc.local_file_cache_path;
+        const prefix_len = $ae_loc.native_device?.hash_prefix_length || 2;
 
-        if (!location_id || !cache_root) return;
+        if (!location_id || !cache_root || is_syncing) return;
 
         is_syncing = true;
-        if (log_lvl > 1) console.log(`Sync Engine: Scanning room ${location_id}...`);
-
         try {
-            // 1. Gather all IDs in this room's hierarchy
             const sessions = await db_events.session.where('event_location_id').equals(location_id).toArray();
             const session_ids = sessions.map(s => s.event_session_id);
             if (session_ids.length === 0) return;
@@ -66,31 +78,21 @@
             const presenters = await db_events.presenter.where('event_session_id').anyOf(session_ids).toArray();
             const presenter_ids = presenters.map(p => p.event_presenter_id);
 
-            // 2. Collect every ID that could have a file attached
             const all_for_ids = [...session_ids, ...presentation_ids, ...presenter_ids, $events_slct.event_id];
-
-            // 3. Find ALL files linked to these IDs
             const files = await db_events.file.where('for_id').anyOf(all_for_ids).toArray();
             
             sync_stats.total = files.length;
             let cached_count = 0;
             let missing_count = 0;
 
-            if (log_lvl > 1) console.log(`Sync Engine: Found ${files.length} potential files for this room.`);
-
-            // 4. Verify and Download
             for (const file_obj of files) {
                 if (!file_obj.hash_sha256) continue;
-                
-                // Fast-track if already confirmed this session
-                if (sync_results[file_obj.event_file_id] === 'success') {
-                    cached_count++;
-                    continue;
-                }
+                if (sync_results[file_obj.event_file_id] === 'success') { cached_count++; continue; }
 
                 const exists = await native.check_hash_file_cache({ 
                     cache_root, 
-                    hash: file_obj.hash_sha256 
+                    hash: file_obj.hash_sha256,
+                    hash_prefix_length: prefix_len
                 });
 
                 if (exists) {
@@ -99,35 +101,22 @@
                     continue;
                 }
 
-                // 5. Download missing file
                 missing_count++;
-                if (log_lvl) console.log(`Sync: Pulling missing file -> ${file_obj.filename}`);
                 currently_syncing = file_obj.filename;
 
                 const url = `${$ae_api.base_url}/hosted_file/${file_obj.hosted_file_id}/download?return_file=true&filename=${encodeURIComponent(file_obj.filename)}`;
-                
                 const result = await native.download_to_cache({
-                    url,
-                    cache_root,
-                    hash: file_obj.hash_sha256,
-                    api_key: $ae_api.api_secret_key,
-                    account_id: $ae_api.account_id
+                    url, cache_root, hash: file_obj.hash_sha256,
+                    api_key: $ae_api.api_secret_key, account_id: $ae_api.account_id,
+                    hash_prefix_length: prefix_len
                 });
 
-                if (result.success) {
-                    sync_results[file_obj.event_file_id] = 'success';
-                }
+                if (result.success) sync_results[file_obj.event_file_id] = 'success';
             }
-            
             sync_stats.cached = cached_count;
             sync_stats.missing = missing_count;
-
-            if (log_lvl && missing_count > 0) {
-                console.log(`Sync Engine: Room scan complete. Cached: ${cached_count}, Downloaded: ${missing_count}`);
-            }
-
         } catch (err) {
-            console.error('Sync Engine: Critical failure in room scan:', err);
+            console.error('Sync Engine Error:', err);
         } finally {
             currently_syncing = null;
             is_syncing = false;
@@ -135,15 +124,66 @@
     }
 </script>
 
-{#if currently_syncing && log_lvl}
-    <div class="fixed bottom-4 right-4 bg-black/80 text-white p-2 rounded-lg text-[10px] z-[9999] border border-primary-500 animate-pulse shadow-2xl">
-        <div class="flex items-center gap-2">
-            <span class="fas fa-sync fa-spin text-primary-500"></span>
-            <div class="flex flex-col">
-                <span class="font-bold">Syncing Room Files...</span>
-                <span class="opacity-70 truncate max-w-48">{currently_syncing}</span>
-                <span class="text-[8px] mt-1 text-primary-300">Room Status: {sync_stats.cached}/{sync_stats.total} Ready</span>
+<!-- Monitor Overlay (Hidden by default, triggered by config modal or secret gesture) -->
+<div class="fixed bottom-4 right-4 z-[9999] flex flex-col items-end gap-2 pointer-events-none">
+    {#if show_monitor}
+        <div class="bg-black/90 text-white p-3 rounded-lg border border-primary-500 shadow-2xl text-[10px] font-mono min-w-48 pointer-events-auto">
+            <div class="flex justify-between border-b border-primary-500 pb-1 mb-2">
+                <span class="font-bold text-primary-400">NATIVE SYNC MONITOR</span>
+                <button onclick={() => show_monitor = false} class="text-error-500 hover:text-error-400">×</button>
+            </div>
+            
+            <div class="grid grid-cols-2 gap-x-4 gap-y-1 mb-2">
+                <span class="opacity-70 text-primary-300">Room Status:</span>
+                <span class="text-right">{sync_stats.cached} / {sync_stats.total} Files</span>
+                
+                <span class="opacity-70 text-primary-300">Prefix Len:</span>
+                <span class="text-right">{$ae_loc.native_device?.hash_prefix_length || 2} chars</span>
+            </div>
+
+            <div class="border-t border-white/10 pt-2 flex flex-col gap-1">
+                <div class="flex justify-between items-center">
+                    <span class:text-primary-500={timer__event}>Event Loop:</span>
+                    <span>{loop_info.event / 1000}s</span>
+                </div>
+                <div class="flex justify-between items-center">
+                    <span class:text-primary-500={timer__device}>Device Loop:</span>
+                    <span>{loop_info.device / 1000}s</span>
+                </div>
+                <div class="flex justify-between items-center">
+                    <span class:text-primary-500={timer__location}>Location Loop:</span>
+                    <span>{loop_info.location / 1000}s</span>
+                </div>
+                <div class="flex justify-between items-center">
+                    <span class:text-primary-500={timer__session}>Session Loop:</span>
+                    <span>{loop_info.session / 1000}s</span>
+                </div>
             </div>
         </div>
-    </div>
-{/if}
\ No newline at end of file
+    {/if}
+
+    {#if currently_syncing}
+        <button 
+            onclick={() => show_monitor = !show_monitor}
+            class="bg-black/80 text-white p-2 rounded-lg text-[10px] border border-primary-500 animate-pulse shadow-2xl pointer-events-auto transition-transform active:scale-95"
+        >
+            <div class="flex items-center gap-2 text-left">
+                <span class="fas fa-sync fa-spin text-primary-500 text-sm"></span>
+                <div class="flex flex-col">
+                    <span class="font-bold">Syncing Room Files...</span>
+                    <span class="opacity-70 truncate max-w-48">{currently_syncing}</span>
+                    <span class="text-[8px] mt-1 text-primary-300">Monitor Ready (Click to View)</span>
+                </div>
+            </div>
+        </button>
+    {:else}
+        <!-- Secret button area to toggle monitor when not syncing -->
+        <button 
+            onclick={() => show_monitor = !show_monitor}
+            class="w-8 h-8 opacity-0 hover:opacity-20 bg-primary-500 rounded-full pointer-events-auto flex items-center justify-center transition-opacity"
+            title="Toggle Sync Monitor"
+        >
+            <span class="fas fa-microchip text-white text-[10px]"></span>
+        </button>
+    {/if}
+</div>
\ No newline at end of file
diff --git a/src/routes/events/[event_id]/(launcher)/launcher_cfg.svelte b/src/routes/events/[event_id]/(launcher)/launcher_cfg.svelte
index ccb2fb09..611494ea 100644
--- a/src/routes/events/[event_id]/(launcher)/launcher_cfg.svelte
+++ b/src/routes/events/[event_id]/(launcher)/launcher_cfg.svelte
@@ -116,6 +116,86 @@
                 </div>
             </div>
         </section>
+
+        <!-- Sync Loop Timers Section -->
+        <section
+            class:preset-outlined-warning-300-700={$events_loc.launcher.show_section__sync_timers}
+            class="sync_timers w-full preset-outlined-surface-300-700 transition-all mb-2"
+        >
+            <h3 class="text-center mb-2 text-sm font-semibold w-full">
+                <button
+                    onclick={() => {
+                        $events_loc.launcher.show_section__sync_timers =
+                            !$events_loc.launcher.show_section__sync_timers;
+                    }}
+                    class="btn btn-sm w-full justify-between"
+                >
+                    <span>
+                        {#if $events_loc.launcher.show_section__sync_timers}
+                            <span class="fas fa-chevron-down"></span>
+                        {:else}
+                            <span class="fas fa-chevron-right"></span>
+                        {/if}
+                        Native Sync Timers
+                    </span>
+                </button>
+            </h3>
+
+            <div
+                class="flex flex-col gap-1 items-center justify-start w-full p-2"
+                class:hidden={!$events_loc.launcher.show_section__sync_timers}
+            >
+                {#if $ae_loc.native_device}
+                    <label class="flex flex-row gap-1 items-center justify-start text-xs w-full">
+                        <span class="grow opacity-70">Event Sync (ms):</span>
+                        <input
+                            type="number"
+                            bind:value={$ae_loc.native_device.check_event_loop_period}
+                            class="input input-sm w-24 text-right preset-tonal-surface"
+                        />
+                    </label>
+                    <label class="flex flex-row gap-1 items-center justify-start text-xs w-full">
+                        <span class="grow opacity-70">Device Heartbeat (ms):</span>
+                        <input
+                            type="number"
+                            bind:value={$ae_loc.native_device.check_event_device_loop_period}
+                            class="input input-sm w-24 text-right preset-tonal-surface"
+                        />
+                    </label>
+                    <label class="flex flex-row gap-1 items-center justify-start text-xs w-full">
+                        <span class="grow opacity-70">Location Refresh (ms):</span>
+                        <input
+                            type="number"
+                            bind:value={$ae_loc.native_device.check_event_location_loop_period}
+                            class="input input-sm w-24 text-right preset-tonal-surface"
+                        />
+                    </label>
+                    <label class="flex flex-row gap-1 items-center justify-start text-xs w-full">
+                        <span class="grow opacity-70">Session Scan (ms):</span>
+                        <input
+                            type="number"
+                            bind:value={$ae_loc.native_device.check_event_session_loop_period}
+                            class="input input-sm w-24 text-right preset-tonal-surface"
+                        />
+                    </label>
+                    <label class="flex flex-row gap-1 items-center justify-start text-xs w-full border-t border-surface-500/20 pt-1 mt-1">
+                        <span class="grow font-semibold text-primary-500">Hash Prefix Length:</span>
+                        <input
+                            type="number"
+                            min="1"
+                            max="8"
+                            bind:value={$ae_loc.native_device.hash_prefix_length}
+                            class="input input-sm w-24 text-right preset-tonal-surface font-bold"
+                        />
+                    </label>
+                    <div class="text-[9px] text-gray-500 mt-1 italic w-full text-right">
+                        * Prefix: {($ae_loc.native_device.hash_prefix_length || 2)} chars. Reload required.
+                    </div>
+                {:else}
+                    <div class="text-xs text-error-500 italic">No device config hydrated.</div>
+                {/if}
+            </div>
+        </section>
     {/if}
 
     <!-- <hr class="w-full my-2 border-1 border-gray-200 dark:border-gray-800 " /> -->