Skills auto change when swapping weapons?

Not sure if I'm dumb or anything, but I haven't found out how to do it at least, but I would love for my abilities to change if I swap weapons. Currently have 3 characters (1 for streaming, 1 for playing alone, 1 for when I play with my friend) and hate that I have to either remap my skills to my second weapon, or waste slots for my primary weapon set on my secondary weapon set.

I think what you're asking for is a separate skill bar that swaps when you swap your weapon-set.

It might sound like a small thing but to me it kinda seems like this could be a pretty big ask from a programming/UI perspective.

I think it's a good idea but I wouldn't hold your breath lol.