Ahoy!
One Flow Man here. I just wanted to make it clear somewhere, since who knows when or if we will ever get the little green check (our game is likely too smol at present to be on Steam's radar).
I do most of my playtesting on the Steam Deck. If something runs poorly on the deck, it's a personal problem for me, so I've done as much optimization as I can for it to run smoothly there. It has full controller support with proper Steam Deck icons, everything should work very smoothly.
And there you have it, Steam Deck support! Arrrrgh!