Proton 9.0-1 released with expanded game support for Steam Deck / Linux
Valve today released the first version of Proton 9.0, the newest stable version of the Windows compatibility layer to run games on Steam Deck and Desktop Linux.
The fact it isn't Steam Deck verified is ironic.
While they do not specifically call it out it seems to help Fallout 4 run better (more stable). At least in my testing so far.