I just went to Preferences and set the resolution of the virtual display to 1920x1080.
I like the idea! Rooting for whoever in the universe working on it! Meanwhile, I think you could actually "mimic" this by using OBS as a virtual camera and use multiple layers to selectively share windows. You can set an output video size, and scale different layers/windows individually.
On a 4k monitor some applications have tiny text and icons, and no way adjust that I can find.