Quitting has a bad UX

[GrayHatter]

Currently, when you open the side bar and tap quit. It opens a popup.

Instead, tapping quit should add a new side bar button below, titled Quit aTox and the original button should be changed into Don't Quit. This would enable power users to open close quickly after learning the combo. And needing to hit two buttons in order, the 2nd being in a very close but slightly different location will prevent an accidental double tap, but staying in the same area doesn't require focusing on a new, 3rd UI element instead of reusing the one they're already looking at.

[theAkito]

Instead, tapping quit should add a new side bar button below, titled Quit aTox and the original button should be changed into Don't Quit. This would enable power users to open close quickly after learning the combo.

I would expect a power user to not require any confirmation, at all.

Maybe it would make more sense to have an advanced setting, disallowing any question for confirmation?

If you learn the combo anyway, then you basically avoid the confirmation by default, either way. So, no need for a confirmation, in the first place.