I am with Alien Brain on this one !
There is no way I would swap four sequencer tracks for two with extra CC’s.
There are plenty of bigger or smaller controllers out there for that purpose, desk space is a silly excuse, one would say in that instance – get the software step sequencer and do it all “in the box”!
Even if it was implemented, I assume it would be on the different layer.
Imagine you want to tweak filter cut-off on that layer but you wouldn’t be able to tweak note pitch or something else on track at the same time.
For that reason I find it rather pointless.
I would rather have better pattern/project management and velocity per drum instrument !
-1000!