If you automate parameters like xpos or ypos in the VST, they won't update when played back unless you force it to refresh by clicking an element in the VST. It updates in the HMD just fine so it's not broken or anything, just not updating for whatever reason.
Hey @imperativity, I'm still having this issue in Reaper as of 12/4/2018. I completely forgot about the fact that I asked this question back in April - any chance you could ping the dev team to see if there's any fix in the works for this? I'm currently using the Oculus Spatializer v1.31.0.
I only remembered this question after googling the issue and finding my own forum post haha.