Since the SUB 37 is more or less replacing the die Sub Phatty, why not use the Sub Phatthys chassis to release a 2 octave Minitaur keyboard synth. The panel should be large enough to put most (if not) all under the hood functions on it? 
I would love a road-worthy MInitaur setup. A little spot for a delay pedal, a little keyboard with sequences or an Arp. Iām kinda winging it using a pedal board but someday the Minitaur suitcase solution will be mine.