With CentOS 7.4, I disabled the gnome power plugin with the following dconf entry:
[org/gnome/settings-daemon/plugins/power]
active=false
I was able to rely on regular X11 DPMS to avoid the GNOME curtain.
Now, it seems there is no longer an active flag on /org/gnome/settings-daemon/plugins/power.
Is there something to replace that?
Jason.