Is it possible to have the VR mirror window set to windowed mode (not fullscreen)?

I’m making an Oculus Rift app but when I start the stand alone build in windows it always start with a black window in fullscreen. When I take the headset on (or cover the sensor), the game displays as it should, but always in fullscreen, no matter what settings I set for getting a windowed “mirror window”.

Is it possible?

Why? Because most apps do it this way, and I like people to be able to use their computer while someone else is playing in VR, and not be hindered by a fullscreen window. You can of course switch app with alt-tab and have the fullscreen window in the background, but I would like it less obtrusive.

Switched to Unity 2019.1.0a14 to get Incremental GC. There it worked right away… It opens a window with the size I have set - no fullscreen.