Tried manual install and the version in the top right corner of the menu says it's installed.
However it's not showing up in the mods list, and the game wont start when trying to run a new game.
The loading screen will finnish but get stuck on a full bar.

Ok I think I've figured out what is happening.
Since the game refuses to launch for me I tried forcing it to run in Proton.
This however makes steam download the windows version of the game.
And that is why the linux installer can't find the install path.

I tried installing the windows version of the patch manually but it still won't show up in the mod list. And the loading screen will still get stuck on a full bar.

So, untill I can get the game to launch natively in linux, I guess I'm stuck to play without the UCP unfortunately.

Does the proton version have all the same issues as the Linux version has? Linux is missing some textures - never looked to see if it was a gpu issue or something else?

Noticeable with red boxes and the emperors faces eyes being really odd.