The only way I've got it to work is through BOME MIDI TRANSFER.
I connect the BBC2 input to one of the virtual BOME outputs and I then have full access to the four sensors in the BBC2.
It is weird how the MIDI monitor in Studio 1 (6.6) shows midi data, but it isn't pulled through to the track.
I had the same problem (and solution) with a Korg nanoKontrol 2.
Perhaps this is something the great guys at Presonus (Gregor in particular) can answer given that in one of his videos he says how great the breath controllers are!