I’ve got about ten hours in on a controller (DualSense) on Steam. One thing: you’ll always get Xbox controller icons if Steam Input is enabled. If you disable that in game properties, you’ll get PlayStation icons for PlayStation controllers.

I had to do this too for the correct icons to show up for the PS in the game.

I have an Xbox controller and I own a PS5 with a few controllers. I’ve tried both and like both. I do like the touch pad curser to help click and start the game from the lauch pad. (I hate lauch pads. They don’t work well with Big Picture Mode and 4K TVs.)

This probably isn’t what you want to hear but you can make a really really great split setup using SteamInput. The only reason I haven’t used it for the final game is because I play a lot on desktop, not just Deck and I don’t have a steam controller. But on Deck with its trackpads I can access most of the UI and still have the trackpads for selecting items and combat. I guess the only big thing you can’t do is move the party with the left stick, but they didn’t bother me too much. I think I might prefer it to either purely kb/m or controller setups.