It takes a bare slip of the finger to close Visidata with the default configuration and lose potentially significant progress with no prompt and no way to undo it as far I can tell.

I would say this borders on an actual bug, no other software does this as far as I can tell, and it makes the software dangerous from my POV.

This can probably be fixed with a clever-enough custom function, but I think it's a major feature that should be part of the main software.