MORPHER 2 is mapped to CC11 Midi (Expression).
MORPHER 1 is mapped to CC10 Midi.
If you can modify the Control Change emitted by the pedal connected to your master keyboard, then you can assign the pedal to Morpher 1 instead of Morpher 2.
EDIT: in the next version, MORPHER1 is mapped to CC9 (CC10 is used in DAW for PAN)