I think it would be a great feature to keep or sync instances states between frames while in presentation mode.
It could behave like the “preserve scroll position”, but for a commom instance shared between screens on a flow.
Since Figma highlights related elements across frames while in prototype view, i think it would be possible do maintain the state of a single instance if subsequent changes were made. So when a user likes a song in a playlist, for example, that satate value is updated across all screens.