Not sure what's going on here quite yet. I was intending to use rwfus to allow LatencyFleX and vkBasalt on the Deck and ran into this issue.

A clean install of rwfus with no additional files added to the overlayed fs will cause Wine-TKG and NorthstarProton to crash. Here's a log file via PROTON_LOG=1. This is reproducible and is resolved simply by uninstalling rwfus.

I am using a copy of SteamOS with Phillip Richter's BTRFS payload and no other changes.