Do not turn off the gnome-settings-daemon xrandr plugin.
Instead, in case there are xrandr-settings from Puavo,
create ~/.config/monitors.xml to match the current display settings
so that gnome-settings-daemon has something sensible to do.
Turn off the udev-hotplug-monitor when a desktop session is on.
(gnome-settings-deamon should be taking care of the displays).
Merge branch 'monitorsxml'

    Use the gnome-settings-daemon xrandr plugin on the desktop sessions,
    and do not interfere with it.  Set things up for it by creating
    monitors.xml when desktop session starts up.