TowerInstance.StampFootprint now writes walkability via SetWalkableBatch instead of per-tile SetWalkable, so despawning (selling) a 2x2 tower fires one OnWalkabilityChanged / enemy re-path instead of four — matching placement and removing the frame hitch on sell. PlaySellEffectRpc now logs a one-time warning when no SellEffectSpawner is in the scene, since a missing spawner silently suppressed the coin VFX and sound.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>