We have very good Steamdeck improvements coming, especially regarding UI/UX to get across the line with Steamdeck verificaiton.
I'm curious what zones you're experiencing that level of performance issues in? I can have my development team take a look at it immediately. Also, is it happening with a specific build you're playing, certain enemies, or other things you can point out? Anything you can point to is helpful for diagnosing and solving things like this.
On a similar note, we just signed an agreement with a co-development studio specializing in console porting and much of the effort there is going to revolve around performance upgrades. Things that are more core as we've already made a ton of improvements related to specific zones, enemies, abilities, and other systems. But, we need to bring that memory foot print down significantly for consoles which we'll be starting work on... Tuesday!