Yeah act 3 is significantly worse optimized than act 1. Should be ironed out in time, but it makes sense given how much time in early access act 1 had that it would be the best optimized.

I’ve lost my entire game thanks to a mod update. Broke all my saves going back just before the Underdark, about 25 hours lost yesterday. Pretty gutting, I’ll probably start again at some point but feeling defeated rn at the thought of all those careful decisions and plodding around, lost.

Re your issue, I’ve seen many, many posts from people using Steam decks that act 3 is practically unplayable especially if streaming to a large screen. I was just about to head to Baldurs Gate, assuming that’s a city type location, and there’s lots of crowds… I noticed that when I got to the Light Inn, performance dropped dramatically. Something to do with pathing all those NPCs and all their interactions isn’t very well optimised. There is a setting for this in the menu, can’t remember what it’s called… dynamic NPC or something like that. Is that setting on or off for you? Might be worth a look.