Setting all those mouse bools to true seems to mean that the mouse doesn’t affect the player’s viewport.
I’m not sure how you’d go about having another player controller rendering it’s camera to the desktop viewport while the VR player just renders to HMD - is that possible? If it’s possible to do it like that, then I imagine you could probably render UMG into it as normal.
Would be much simpler if it was possible to just add UMG to the VR spectator window though, and it’s not clear to my why that wouldn’t be possible. Perhaps an Epic VR dev can weigh in here…?