Is it possible to have the VR mirror window set to windowed mode (not fullscreen)? - Unity Answers
Nibre on Twitter: "What the update will include; In-game MotherVR settings menu, new VR Controller Input (with matching UI!), new Mirror View, visible Intro+Loading screens for SteamVR, force-quitting and auto audio-device routing
HOW TO RECORD VR GAMEPLAY! Using oculus mirror, optimal settings and removing black edges - YouTube
SteamVR Best Practices in Unreal Engine | Unreal Engine Documentation