Easy Open FSR manager that detects all your compatible games and lets you install and configure it from one UI
https://github.com/fholger/openvr_fsr/ 

Open FSR is a super sampling you can apply to just the center portion of the screens. You set the radius and beyond that the effect falls off.
Makes for cheaper SS but you can also save performance if you run a potato buy setting steamVR to half res then applying super sampling to the center.