The new Star Wars Xcom game says it's unsupported on Deck and Machine. I know those aren't always entirely accurate. I didn't suppose anyone's gotten the game and tried it have they?
According to https://steamdeckhq.com/news/star-wars-zero-company-not-good-on-steam-deck/ the playing on Deck is a bad time, struggles to hit 30 fps (often 18 to 22 fps in action) with lowest settings applied. I don't know about the resolution, probably native 720p or 800p, and if he tried upscaling. But at this performance level, I do not think it will help to get stable 30 fps.