Answering here. 
Did you already to programmed the RK002?
This is just an idea I had answering you to differentiate midi informations for each audio track from a single midi track : using notes 36-43, you can map each note velocity to a CC with a different midi channel, and 1 (2 or 3) lfo depth.
In that case, audio tracks have different channels.
Many possibilities!
You can map other notes velocities.
You can map certain CC number range to certain midi channels :
CC 16-23 channel 1 > mapped to 8 x CC16 (Pitch), with channel 1-8
You can map a specific CC value ranges.
Ex with pitch CC16 channel 1, chromatic values Octave 1 :
Values 0-11 mapped to values 0-60 CC16 channel 1
Values 12-23 mapped to values 0-60, CC16 channel 2