wow… I hadn’t thought of that until you mentioned it but a trackpoint in thumb’s reach on a steamdeck-like device is a great idea. And good marketing continuity for Lenovo

In addition to everything everyone else has said, the launch option: PROTON_LOG=1 %command% (from the wiki). It will create a steam-<gameid>.log in your homedir which can have lots of good wine/proton specific information in it.

You can also rename the user-settings.sample.py file in a given proton version in $HOME/.steam/root/steamapps/common/Proton - <version>/ to user-settings.py and uncomment the additional wine debugging options (PROTON_LOG is already set in this file, but it is not active until it’s renamed or passed directly on the Launch Options line).