Just want to confirm that I have been having terrible stutter issues in VR that I was not able to solve until finding this post.
I have a Pimax Crystal and RTX4090, and around my local airport (KFIT) performance is spectacularly good (using DLSS4); however, flying north into NH would eventually produce horrible stutters every time, so bad that I had to stop playing. Some sessions were better than others, but ultimately very unstable. I tried turning down many settings, but nothing worked (including turning HAGs on/off) until I found this post and turned fauna completely off. Now the performance is good everywhere. I haven’t tested exhaustively yet, but looking like there is definitely a problem with fauna in VR.