So you're having a hard time keeping your head still in order to push the buttons in the pit?
If so, I had that problem when I first got my TrackIR, it just took time to get used to keeping my head so still, but eventually I got it and now I can press buttons just fine. If you still can't get it then perhaps programme the TrackIR pause button onto your HOTAS so that you can look to say the CMS panel, press the button on the HOTAS to pause, do what you need to do, then unpause.
What you're describing might be when the sensors are tilted so much so that the TrackIR can't pick them up, then the screen jitters and moves violently. I'd say to fix that you would have to make the TrackIR sit at head height and make sure the sensors are aligned to the middle of the TrackIR, you can check to see if they're aligned in the software