Is possible, map in the matrix Pitch Global to the Ribbon (Amount to max + or anything in 12 note value - the previous OS was a little "out of tune" that's what I saw in a video, where the guy had something like 26 as value), set VCOs Tuning to Continous, the Ribbon Mode can be set as pleased...
The centre of the ribbon is of course the root note, moving the finger across the b/w keys should match the appropriate note - relative to the root note!
I hope I did not forget anything - as I am not in the studio right now.
I am practicing this currently and it is fun. Especially as the CC values are not transfered to a possible slave synth.
EDIT: If you split the keys you can play the chords on the lower section with one hand, play the Theremin on the upper half, and use your nose for the ribbon :-) just joking. Best is to have a slave synth doing the chords. PB should be set to mono or unison the chord goes through to the slave synth anyways.