Oro

Halo 2 mod tools seem to be broken for me when running under Proton with the required tweaks, not loading into any menu at all. Everything else seems to work fine, although with some windowing errors (I would suggest running through gamescope to fix that)

the components required are included inside of winetricks (as vcrun2015, d3dcompiler_47, and msxml3), so you don't need to manually add the files. GloriousEggroll has also put together a gamefix for the mod tools that allows them to run, and the process to get it to work is just to use a Proton-GE version that has the necessary fixes applied. Other than changing the Proton version, getting it to run is the same as the Windows version. Be sure to extract the file it needs before running it, otherwise it won't work!