Some behaviour is different between VR and Desktop so it would be great to be able to check for that.
As PhaxeNor stated: "IsUserInVr" was added in a previous update.
"IsUserInVr" has been added in UDONSDK-2020.02.23.14.05_Public
I personally use VR testing to give UI elements to Desktop users. It would be nice if there were a built in way to detect this that wasn't jank.
Adjusting collision to better accommodate each mode would be another use case.
Use case example would be flying vehicles that has different controls if you're on desktop or VR