If you manage to turn off your HDMI screens using CEC out of Intuiface, just using your current hardware and OS, that would be a good start and a lead to investigate to do it from Intuiface after.
If you manage to turn off your HDMI screens using CEC out of Intuiface, just using your current hardware and OS, that would be a good start and a lead to investigate to do it from Intuiface after.