What is a huge improvement on my setup (i5-10400, rtx3070, 16GB RAM) is to deactivate every second screen and set the main screen (not vr) to a resolution like 1024*768.
I think every pixel the GPU has not to render except VR, helps the VR rendering process.
I put everything on high and scaling to 80, Detail lvl to 40 and objects lvl to 55 and everything is running smooth. But i am still experimenting. Also, i am tweaking the 3070 to 120% power with OC