"All layers" for paint bucket tool

[_fluffy]

I'm still trying to figure out how I'm going to do my comic/illustration art in Affinity Photo. Right now the workflow I used in Photoshop (magic wand to select an area, expand selection by a few pixels, eyedropper to select a color, "fill selection with primary color" command) is pretty awkward to do because of a bunch of little usability papercuts I've posted about elsewhere on the forum.

So I'm trying to use the paint bucket tool instead, and I'm rather surprised that there's no option to constrain the paint bucket to all layers - the only options are current layer, current & below, and layers beneath. Since my flat fills layer is below my ink layer, this makes it not very useful without taking even more extra steps (such as moving the ink layer under the flat fill layer while I'm doing my flats).

I'd really like to be able to switch to this program instead of continuing to pay ridiculous amounts for Photoshop. Right now I'm having a really hard time recommending this to others, though.