It’s the way the HMCS must be projected. It is always in the center of the screen. If you don’t have a head tracker, by using the mouse to pan for example, the view moves, but the HMCS stays put. VR works the same. the scene gets panned when you move, but the hmcs stays in center view and you are always looking at the center of the VR screen.
No matter if its 1 x ? or 1:1 with TIR, you are always forced to move your head ‘AWAY’ from the center of the screen where the HMCS always resides.
To fix this, BMS would need to use a completely different panning system if a tracker is being used and would need its own ‘track’ profile to be configured for all 6dof’s which moved the HMCS position along with the screen pan (at a different rate). I think it might be possible, but very complex and frankly would probably look and feel weird with image distortion close to screen boundaries (especially in wide format), if not totally nauseating, I think there’s lots more useful features to be added to BMS including VR ( 😉 )