This is a wonderful idea, but falls down when you think about how it will actually work. Right now the sequencers relay three bits of MIDI data: note-on/off (gate), note number (pitch) and velocity. Y'all are going to want to replace those with CC's and be able to change those CC's on the fly, no doubt. Without redesigning the whole interface workflow, how would you change the CC assigned to the sequence when not tethered to a computer? Being stuck with the same three CC's to sequence really then makes that sequencer tied to whatever synth the CC's were setup for. S'okay if you use all gear from one company like, say, Waldorf, to an extent, as the CC's do change too much from synth to synth, but still the Blofeld throws a blanket over that fire.
A Controller Change sequencer is a bloody unreal idea and you gotta wonder why NOBODY has done it before. So you wonder about why they haven't and you realise what I explained above. Squarp's Pyramid does it, along with a couple of others, but they are all in the 1000aud+ range. It cost a lot of money to workout how to implement in-the-box control and configuring of these functions. Visit the Squarp forums for a sneak peek into the the world of sequencers that try to be everything to everyone.