SteamVR OSVR driver with angular velocity data provided to SteamVR so it can do it's orientation prediction without stuttering.
This is a binary of the source in https://github.com/mdigkin/SteamVR-OSVR
Extract file to (probably c:/Program Files/Steam/steamapps/common) SteamVR/drivers/osvr/bin/win64, overwriting the previous directory contents.