Add TrackIR (and by extension FreeTrack) support to control the view independently of the pitch/yaw axis, since those get locked/used for control in alt mode.

It's a system to use the irl head orientation, to look around in games. It would make flying planes and helicopters in first person much more enjoyable.

They provide an UE plugin, as well as a quick start guide
https://docs.trackir.com/trackir-sdk/unreal-engine-quick-start