I feel like someone should mention for those who don't know, this is the Linux User Group's (LUG) tool to help you set up Star Citizen to run on linux. It's quite helpful.
I will say it runs quite well on linux. I miss my Tobii 5 but have got a decent standin using an oldish iphone and OpenTrack. My racing pedals needed a small app to work because Proton sees they have no button and disregards them, and everything else just works.
performance should be the same. the big win is protonfixes, so when things change for SC we can get those into fixes that run automatically at every game launch instead of having to ask people to change things manually in lutris. at the moment these enable the launcher to be able to Verify, and patches Nvidia so that DLSS works