I have been running a few experiments with the vive liptracker and methods on how to improve the tracking. One of the experiments I ran required me to make a registry edit to allow vrc to run at a higher CPU priority. I was unable to do it in Task manager. I know that there are some launch options for AMD cpu's to run on specific cores, but I have noticed significant improvement in facetracking by setting the process priority to high or real time for the following applications:
VRChat (registry edit is needed to do this. Not recommended if you don't know what you are doing), HtcConnectionUtility.exe, steamVR, VRCFaceTracking UI, and SRanipalRuntime.
Doing this has made my facetracking a lot smoother for me. Also others that have seen my facetracking have noticed it's smoother and less jittery.
TL;DR I would like to have launch options to set a higher cpu priority for VRChat without editing the registry.