When you lean in, your in-game head moves closer to the front of the cockpit. You can use your zoom toggle key/button and zoom in and out like normal - TIR does not control the zoom in the game, only your head position. It's easy enough to enable/disable the TIR with a button, for those times you don't want your head to move all around; like with GV's or if you have no dead zone in the TIR profile and you want a steady head while your shoot.
The TrackClip Pro clips onto your headset and has a little bit of articulated movement to get the emitters lined up with the reciever, but I'm not sure how much you'd need with a headset that wraps behind your head.