I think the problem here is that most controllers use the Mackie Protocol.
The Qcon Pro-X has features which are added to the original protocol?? (Master leds & second display strip)
For these to work, Steinberg has to add them to Cubase/Nuende, right?
But if every other manufacturer adds different features to the existing protocol, Steinberg would have to adress this for every single controller, which they most likely won´t.
Unless new features are officially added to the Protocol itself. The protocol is there to unify this stuff.