With the MxB hooked up to a DAW via the USB MIDI interface or an external MIDI interface, expression pedal motions are not being transmitted as MIDI CC messages!
According to the MxB manual, Exp 1 and M3 are summed, as are Exp 2 and M4. This is clearly what's happening for local control, but MIDI Out just transmits the M3 and M4 motions as CC messages, not the sums! Why on earth? Is this design or defect?
Moving an expression pedal only provides local control, and this works even when local control is disabled in Arturia MIDI Control Center! This strikes me as rather illogical.
PLEASE: add transmission of Exp 1 and Exp 2 as SEPARATE MIDI CC messages in the MIDI implementation of the upcoming MxB software update.