Overlays on Bangle.js 2

missed the Bangle.js 2 part.

Yes, unfortunately it's just not possible on Bangle.js 1 because we have no offscreen buffer. But on that we do at least have the ability to scroll down and display stuff at the top of the screen (which Bangle.js didn't have).

what about the input controls on active overlay, especially the touch?

That is unchanged. It's a bit of a minefield to be honest, but you could write some code to remove input handlers and reinstate them after if needed. Maybe that could be turned into a library that others could use