As it is possible that there is still no good midi controller specific for cubase XD
Some pads, knob, fader, that works perfectly with Groove agent, that can be sequenced from the controller, with visual feedback, lights etc.
All DAWs have PUSH, ATOM, FIRE…
I hope you are already in it Mr. Steinberg 
nobody wants this?
Yes
mini Nuage with one or more Mfaders
like Behringer Presonus or iCon
d
no, no I don’t mean a control for the mixer, (of that there already a lot) what I suggest is more for control of groove agent, the midi sequencer to produce drum, melodies from a physical control.
more like push, atom, fire
Of course some knobs and some fader would be good.
I think that is a very bad idea. The control surface should be generic and work with any daw. It should also be made by anyone. In the same way as a audio interface or mouse. It need to be standardised. If you build a specific one you will end up with something that only works with specific versions. The protocol should be generic. It should not matter if it was faderport sized unit or a 88RS console size. There is a MIDI2.0 specification ongoing but so far it seems to have been good if it was when it should have been done in 1990. Today ut should be build as a internet standard or a AES. It seems like the only one that had tried to do something is Euphonix but they have been bought by AVID so it wont be a proper standard. I dont get it why yamaha accept this. AVID do great controllers, but they also bound the customer to their ecosystem. Yamaha seems not be in the game however Presonus have entered the arena with controllers and software.
if that would be wonderful, but currently it is not possible to make a good controller well integrated, if it is not steinberg who does it.
since the midi falls too short for a good integration.