[SOLVED] Silent Hunter 3 & Living Silent Hunter 3 Supermod - Steam proton + JSGME question

Hello guys! Recently re watched Das Boot (amazing film btw for those who haven't seen it, highly recommend) and that inspired me to install my SH3 from steam. The thing is its the first time I'm going to be playing on Linux, and I'm a bit stumped on how I can install the LSH3 supermod. The instructions for the 2022 version of LSH3 state that you simply run the provided .exe (due to this being steam proton I placed it in the game directory but this doesn't seem to be required) and run it. However I can't seem to figure out how I can use an existing proton environment to run an executable which is not the actual steam game for that environment. Can anybody help with this?

As a bonus question, because this game is quite old there are quite a few mods available for it, and the best way to activate them after downloading (on windows at least) is through JSGME. However I also cant figure out how to install that in the game directory. I have downloaded its installer but dont know how to actually run it.

I have included the link to the LSH3 2022 install manual as well as a screenshot of my game directory with files related to this post circled.

Any insight would be amazing!