What should I do when I need to show a coworker something on my screen?
That said, I don't think it supports casting "back" to the laptop that you're using for Mac Virtual Display. That would be a big improvement I think.
Realistically, if it's something on my Virtual Display, I just take of the VP for a moment and my MBP screen comes back on.
ETA: I just tried to stream back to the MBP that I'm using with Mac Virtual Display. It "works", but not in the way I'd hoped. My view is streamed to the MBP, but the screen doesn't come back on - instead, the virtual display shows what I'm seeing in the headset. Not helpful, and more than a bit nausea-inducing :(.