I've removed the Xbox gaming app completely again as I'm currently going through all of the troubleshooting steps provided on the help page again. I kept trying everything and freshly installed windows. You could go higher on the presets, but expect frame rates to drop around the teens, which makes doing anything outside of standing still pretty miserable. My os is running from my C: and I'm hoping to pre install starfield on my E: which is an M.2 nvme which works perfectly. I did find that if you knock the overall preset down to low, you'll easily get to 30 fps outside of towns, but at the cost of detail that I wasn't comfortable losing. During gunfights or more hectic scenes, the fps also hovers in the low 20s.

Expect a hit around the low 20 fps in more densely populated areas like New Atlantic (I was getting 18-22 fps near the landing pad). You'll hover around 25 fps when exploring space at these settings, and probably only get an hour or so of battery life. Playing Starfield at 30 fps on the Steam Deck is possible but will require some tweaks. Best Settings for Starfield on the Steam Deck What are the best Steam Deck settings for Starfield?

Instaling Starfield