Which desktop environment honours the DISPLAY setting

[allistarM]

I have a 6 monitor setup across two xscreens. The left hand xscreen is four monitors in a grid running KDE Plasma. The right xscreen is two monitors vertically stacked. I run compiz across all. Running compiz means I don't need a desktop environment running on the right xscreen.

My dilemma is that it's becoming harder to keep compiz updated. This is a shame because it works very well. The KDE compositor is no where near as functional or smooth.

Plasma won't run on both xscreens. I can't run plasmashell twice. As it I have modified the kde-plasma/plasma-workspace to force it to ignore the right two monitors (it identified monitors by their port name which doesn't work when these are not unique).

I'm looking for a desktop environment that will run on the second xscreen. I haven't found one that will honour the "DISPLAY" environment variable. E.g. I want to do this:
DISPLAY=":0.1" startde
(where "startde" is the command to start the desktop environment).

LXQT doesn't work as it gets confused when Plasma is already running.
Enlightement ignores the display variable and tries to start on the xscreen that Plasma is running on.

Does anyone know of a DE that will run only on the xscreen I tell it to?
Thanks.

[Dominique_71]

fvwm3 will do it. Even fvwm2, but fvwm3 have extended multi-monitors features.

[allistarM]

Thanks, I'll look into this. For now I have updated the compiz ebuilds so there aren't any warnings in portage and so they build. I'll stick with compiz until it absolutely doesn't work anymore.