While this is also that I miss being able to tinker with "natively" with Nvidia, you can upgrade FSR with PROTON_FSR4_UPGRADE, same with PROTON_DLSS_UPGRADE, limit FPS with either DXVK_FRAME_RATE or something else like mangohud, and ReShade does exist on Linux, you just load it differently, same with stuff like Lossless Scaling. I don't know what kind of optimizations you use from AMD, but on Nvidia it's literally just preconfigured graphics settings. Anticheats are shit from a butt, yeah.