Yes, I had similar "wobbles" at first, but got rid of them by tweeking parameters in PiTool: *maybe* it's "motion compensation" of something on that page!! That became butter smooth!!
Yes, at least with Steam version of Aerofly RC10, you can easily use your Pimax 8kx - it works perfectly, and it's a wonderful experience!! (would be perfect if Aerofly would let use the switches on our transmitters, as actually you need to take off the headset to see the keyboard...)