So I managed to do a thing. I think Wine 9.0 must have introduced some big fixes because #Affinity Designer works now! With some tweaking, of course, but it's pretty cool to see nonetheless.
Designer v2 is still a no-go, relying very heavily on new Windows features that haven't been replicated yet in Wine; unfortunately, most of my files are now in v2 format so this isn't an ideal solution. Still, I can use v1 again, and that's better than nothing.
