diff --git a/lib/upload-manager.js b/lib/upload-manager.js
index 220a249..f08210f 100644
--- a/lib/upload-manager.js
+++ b/lib/upload-manager.js
@@ -310,18 +310,30 @@ class UploadManager extends EventEmitter {
     this._batchResults = results;
     this._additionalPromises = []; // Track jobs added mid-batch via addJobs()
 
-    for (const task of tasks) {
-      const fileName = path.basename(task.file);
-      if (!results.has(task.file)) {
-        let size = 0;
-        try { size = fs.statSync(task.file).size; } catch {}
-        results.set(task.file, { name: fileName, size, results: [] });
+    const DEDUP_CHUNK = 200;
+    for (let i = 0; i < tasks.length; i += DEDUP_CHUNK) {
+      const end = Math.min(i + DEDUP_CHUNK, tasks.length);
+      for (let j = i; j < end; j++) {
+        const task = tasks[j];
+        if (!results.has(task.file)) {
+          const fileName = path.basename(task.file);
+          let size = 0;
+          try { size = fs.statSync(task.file).size; } catch {}
+          results.set(task.file, { name: fileName, size, results: [] });
+        }
       }
+      if (end < tasks.length) await new Promise(setImmediate);
     }
 
     this._startStatsTimer();
 
-    const promises = tasks.map((task) => this._runJob(task, results, signal));
+    const SPAWN_CHUNK = 100;
+    const promises = [];
+    for (let i = 0; i < tasks.length; i += SPAWN_CHUNK) {
+      const end = Math.min(i + SPAWN_CHUNK, tasks.length);
+      for (let j = i; j < end; j++) promises.push(this._runJob(tasks[j], results, signal));
+      if (end < tasks.length) await new Promise(setImmediate);
+    }
     await Promise.allSettled(promises);
     // Wait for any jobs added mid-batch via addJobs()
     while (this._additionalPromises.length > 0) {
diff --git a/main.js b/main.js
index b5448da..957b81c 100644
--- a/main.js
+++ b/main.js
@@ -216,23 +216,10 @@ function rotLog(msg, ts) {
   try {
     const iso = new Date(ts || Date.now()).toISOString();
     const line = `[${iso}] ${msg}\n`;
-    // Write synchronously. Rotation events are rare (a handful per batch) so
-    // the batching optimization from debugLog doesn't buy us anything, and
-    // syncing guarantees the user can refresh the file and see fresh entries
-    // without waiting on a flush timer.
-    const candidates = [
-      getRotLogPath(),
-      path.join(app.getPath('desktop') || app.getPath('userData'), 'account-rotation.log'),
-      path.join(app.getPath('userData'), 'account-rotation.log')
-    ];
-    for (const target of candidates) {
-      try {
-        fs.mkdirSync(path.dirname(target), { recursive: true });
-        fs.appendFileSync(target, line, 'utf-8');
-        break;
-      } catch {}
+    _rotLogBuffer.push(line);
+    if (!_rotLogFlushTimer) {
+      _rotLogFlushTimer = setTimeout(() => { _rotLogFlushTimer = null; _flushRotLog(); }, 500);
     }
-    // Mirror into the main debug log for single-file-grep convenience.
     _debugLogBuffer.push(`[${iso}] [ROT] ${msg}\n`);
     if (!_debugLogFlushTimer) {
       _debugLogFlushTimer = setTimeout(() => { _debugLogFlushTimer = null; _flushDebugLog(); }, 500);