hit_effect/firework is the cabinet's 13-frame spark (additive art), and the skin turns on note_arc_firework_cabinet: 9 sparks, the first at frame 5 and then every 3 frames, each sitting where the note passed, centred on it at full size and added onto the scene. Only hit big don/ka get it, not big drumroll hits.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>