Interesting, for those wondering how this could be useful apart from what's already mentioned in the Readme: Projects like my Weylus [1] or the similar Deskreen [2] would greatly benefit from this as both can mirror your screen to a tablet and like that one could use a dummy display and said tablet to create an additional screen.

On a related note, does anyone know of similar software to create dummy displays on Linux? All I could find so far is some trickery which only works with Intel hardware on X11 [3].

[2]: https://github.com/pavlobu/deskreen

[3]: https://github.com/H-M-H/Weylus#intel-gpu-on-xorg-with-intel...