The last time I used TrackIR in Reforger, it worked, but was buggy. For the most part in ArmA 3 TrackIR is plug and play, in Reforger I had to spend a significant amount of time tuning the application so my head movement wasn't exaggerated 100x compared to ArmA 3, e.g. I look to the left 10 degrees and my camera does a 720 degree rotation.