Just wanted to add I’m experimenting with OpenXR on Unreal Engine with Windows Mixed Reality, and started getting really annoyed about SteamVR opening every time. I had the SteamVR plugin disabled, but the issue was not resolved until I also disabled the Oculus VR plug-in. There’s clearly some legacy dependencies going on there. I now only have Windows Mixed Reality and OpenXR options selected, and SteamVR no longer opens.