4.25 is out and comes with some interesting remarks allowing a spectator view for the Hololens 2, this is equal to what’s already possible with Unity:
While there is some documentation since Unreal 4.23 about Hololens Streaming there is currently no documentation about how a third party camera in Unreal is linked to the physical camera streaming a life image directly into the Editor. According to the Unreal Hololens presentation here: https://youtu.be/yeMN-CToJJQ?t=645
This is done by a similar camera setup as with Unity Hololens Spectator View. But unfortunately the video is a bit to less to build-up the setting on our site. Could someone give us a hint or help us on this?