with the latest 1.5 patch you can easily reach 60fps during normal gameplay (all low settings, FSR3 frame gen enabled). you can even reach 90fps incertain cases. its honestly impressive what they were able to squeeze out of the steamdeck.
https://www.protondb.com/app/2420110?device=steamDeck
I’m sure your desktop plays it better, but it should now work on the Deck despite the unverified status (this is the case more often than not).
You can always stream from your desktop to your Deck too if the performance on the Deck isn’t great.
I do this with my PS5 sometimes. I played the majority of Miles Morales that way.
Hey, what was it that you didn’t like about BG3? I haven’t played it yet because my patience for RPGs is low these days.