I'm not an expert but I can show you what works for me.
I don't use Steam VR, you're just adding another thing in the middle that's not really neccesary.
These are my settings, almost all on the low side of the spectrum with a 2060. With your GPU you should be able to crank them much higher.
Settings that kill your fps are, in my experience, MSAA and supersampling most of the time.
Open XR and Oculus debug tool are not neccesary, what I use is Oculus Tray Tool, it can change most of the same settings.
With all these I get between 36-72 fps (with reprojection activated) as long as I'm not above Dubai in the Persian Gulf map. At high altitude in simple missions it goes above 72 sometimes.
I play with an usb cable. Intel 10400F, 32GB RAM, 2060.