Not sure how helpful this will be, but if you play on two different machines, you don’t have to worry about split screen. So I play on my laptop with a PS4 controller and my brother (eight hours away) plays on a steam deck. We play multiplayer together. Different controls but since we’re on two different machines, we don’t have to deal with split screen and we can just do our own thing on each screen. Not sure whether this will address your problem, but you can play multiplayer without doing split screen.
