I’ve tried to set this up a while ago with my MPK25. learned a lot about midi in the process. theoretically the generic remote in cubase should work with NRPN but looks like the function is broken.
I even opened a support ticket with Steinberg, took a while to get them to understand what the issue was. in the end they said its a bug that this doesnt work and will be fixed someday…
so in the end, getting a keyboard like MPK with endless rotary knobs is kinda pointless (if you use cubase). now I just use them as standard knobs, sending values from 0 to 127 for which the traditional knob is better since you have an idea where is 0 and where is 127.