I'm going to replace Option "UseDisplayDevice" "none" with Option "AllowEmptyInitialConfiguration" "on".
The gpu-manager will only require that Option "ConstrainCursor" "off" and Option "AllowEmptyInitialConfiguration" "on" are in your xorg.conf.
This will give you access to all the outputs connected to the discrete card.
I'm going to replace Option "UseDisplayDevice" "none" with Option "AllowEmptyInit ialConfiguratio n" "on".
The gpu-manager will only require that Option "ConstrainCursor" "off" and Option "AllowEmptyInit ialConfiguratio n" "on" are in your xorg.conf.
This will give you access to all the outputs connected to the discrete card.