I saw a somewhat similar thread being made in Feb 2022 but I’d like to request it anyway. In paint dot net if you hold Shift with Paint Bucket tool, it switches to non-contiguous (global) fill for the time you’re holding the key. Something similar would be great for Aseprite.
Switch Contiguous fill shortcut doesn’t do the job the same way because it has to be a whole separate unique key and it’s a toggle, not hold/release behavior.