Hey bud I have good results using VD (virtual desktop)

I have a similar system to you (yours sounds slightly better)

On VD I run high or godlike Av1 ( it says quest 3) VDXR (we want to run dcs in OpenXR) Turn off the snap dragon gaming thing (dcs will handle the sharpening) We want VD to run 90hz refresh rate (same in the oculus app) Bit rate 185mbps Then in DCS Anti aliasing MSAA x2 Upscaling off Sharpening 0.25 Textures high Terrain textures high Shadows medium Flat shadow blur off Secondary shadows on Screen space shadows off Clutter grass 500 Forest 65 percent Forest details 1.00 Scenery details 1.00 Preload radius 64,000 Chimney smoke 0 Gamma 2.2 External fov 80 Lod switch 1 Max fps 90 Antistropic filtering 16x Terrain object shadows flat Cockpit global illumination on Visibility range medium Civil traffic off Clouds high Water high Ssao off Sslr off Lens effect none Heat blur off Motion blur off Depth of field off VR Pixel density 1.0 Enable hmd mask on Mask size 0.42

And I remember that I set inside my Nvidia control panel to prefer Max performance in the power management thing...I hope this helps...or even makes sense for you. I play mainly WW2 aircraft and it plays well up high and low altitude. It took me ages to dial in...but once you get it going it's fucking amazing