I am messing around looking for a way to expose a virtual display as a VNC service to use a phone as a secondary display. People suggest to add the
VirtualHeads option in the device section. The way I am using is the following snippet:
services.xserver.deviceSection = '' Option "VirtualHeads" "2" '';
And I expect two VIRTUAL outputs appearing when I run xrandr.
From this I could expose those displays using x11vnc.
I am already using an external monitor.
EDIT 1: My device is a laptop i5 7200U with an Intel Graphics 620. My current workaround is mirroring a terminal session in an external display (old tablet) using gotty and tmux, after it’s running it runs fast enough xD.