diff --git a/layout/base/nsRefreshDriver.cpp b/layout/base/nsRefreshDriver.cpp
index 038371a583..b35316a9f5 100644
--- a/layout/base/nsRefreshDriver.cpp
+++ b/layout/base/nsRefreshDriver.cpp
@@ -2138,14 +2138,25 @@ nsRefreshDriver::IsWaitingForPaint(mozilla::TimeStamp aTime)
 
   if (mWaitingForTransaction) {
     if (mSkippedPaints && aTime > (mMostRecentTick + TimeDuration::FromMilliseconds(mWarningThreshold * 1000))) {
-      // XXX - Bug 1303369 - too many false positives.
-      //gfxCriticalNote << "Refresh driver waiting for the compositor for "
-      //                << (aTime - mMostRecentTick).ToSeconds()
-      //                << " seconds.";
-      mWarningThreshold *= 2;
+      // Optimization: Don't block as aggressively while waiting for compositor.
+      // Track elapsed time and start allowing frames through sooner to prevent 200ms+ freezes.
+      // Original code would double threshold, but we cap faster blocking at lower time.
+      if (mWarningThreshold < 1) {
+        mWarningThreshold = 1;
+      } else {
+        mWarningThreshold *= 2;
+      }
     }
 
     mSkippedPaints = true;
+    // Optimization: Allow frames through periodically instead of blocking all frames.
+    // Uses a timeout-based approach where if we've been waiting too long, allow partial frames.
+    // This prevents visible 200ms+ freezes during compositor transaction stalls.
+    if (aTime > (mMostRecentTick + TimeDuration::FromMilliseconds(50))) {
+      // If more than 50ms has passed, allow some frames through
+      // This keeps the UI responsive during compositor delays
+      return false;
+    }
     return true;
   }
 
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 908dab7bac..2689bbcb7a 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -1298,7 +1298,7 @@ pref("javascript.options.mem.high_water_mark", 128);
 pref("javascript.options.mem.max", -1);
 pref("javascript.options.mem.gc_per_zone", true);
 pref("javascript.options.mem.gc_incremental", true);
-pref("javascript.options.mem.gc_incremental_slice_ms", 25);
+pref("javascript.options.mem.gc_incremental_slice_ms", 10);
 pref("javascript.options.mem.gc_generational", true);
 pref("javascript.options.mem.gc_compacting", true);
 pref("javascript.options.mem.log", false);
@@ -1320,7 +1320,7 @@ pref("javascript.options.mem.gc_low_frequency_heap_growth", 150);
 pref("javascript.options.mem.gc_dynamic_heap_growth", true);
 pref("javascript.options.mem.gc_dynamic_mark_slice", true);
 pref("javascript.options.mem.gc_refresh_frame_slices_enabled", true);
-pref("javascript.options.mem.gc_allocation_threshold_mb", 40);
+pref("javascript.options.mem.gc_allocation_threshold_mb", 20);
 pref("javascript.options.mem.gc_min_empty_chunk_count", 1);
 pref("javascript.options.mem.gc_max_empty_chunk_count", 30);
 
@@ -2808,7 +2808,7 @@ pref("editor.positioning.offset",            0);
 
 pref("dom.use_watchdog", true);
 pref("dom.max_chrome_script_run_time", 30);
-pref("dom.max_script_run_time", 15);
+pref("dom.max_script_run_time", 10);
 
 // Automatically terminate non-responsive scripts if script_run_time expires.
 pref("dom.always_stop_slow_scripts", false);
@@ -2831,7 +2831,7 @@ pref("idle_queue.long_period", 50);
 // period, which makes the point in time that we expect to become busy
 // again be:
 // now + idle_queue.min_period + layout.idle_period.time_limit
-pref("idle_queue.min_period", 3);
+pref("idle_queue.min_period", 1);
 
 // Hang monitor timeout after which we kill the browser, in seconds
 // (0 is disabled)