Feature request: Viewport-based animation triggers

Viewport-based animation triggers
Animations should be able to start when their component enters the viewport while scrolling in Prototype mode, rather than starting immediately when the parent frame loads.

Suggested controls:

Start when entering the viewport
Configurable visibility threshold
Play once or replay on re-entry
Pause, continue, or reset when leaving
Optional delay
Independent playback from the parent frame’s timeline
This would make animated components practical in long, scrollable page prototypes and allow multiple animations with different durations and start positions to coexist.