User goal clarified: the wildly fluctuating FPS/ms IS the target. Root cause is per-frame throwaway allocations triggering periodic gen2 GC pauses = the spikes. Plan takes only the easy, bit-identical, non-faithfulness-sensitive buffer-reuse sites from the 54-site audit (animation pose buffers, particle draw-lists/iterator, interior partition, trivial per-frame HashSets); defers the two risky sites (EnvCell settled-camera gate, physics Transition pooling). Gate = the existing frame profiler before/after (alloc_kb down, cpu_ms max/p99 tighten) + identical visuals. Loading/pak work parked.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>