1. Have AMD GPU (Radeon 6800m)
  2. Open VRChat
  3. Go visit this world: https://vrchat.com/home/world/wrld_bd1949f5-54df-4cea-8a58-083eb60bfe33/info
  4. Look around, world operates fine
  5. Turn on "Volumetric Lighting" setting
  6. World stutters very badly with bad SteamVR headset timing
  7. Can turn setting on and off to make stuttering go away and come back reliably
This is the second world in which lighting features to be a problem with AMD GPUs and stuttering, but this time it's a specific setting that shows it to happen.