Oh great, I feel almost convinced!
I think, if I’m reading correctly that is, the Motu M2 would be powered by the iPad Pro through the USB-C port. As I’ve got the Magic Keyboard for iPad, which adds a USB-C port for power, I could charge the iPad through this port. while the iPad powers the M2.
Although it doesn’t look as portable as the U24 and I doubt I’d go anywhere further than my garden anyway, I could use a battery pack to charge the iPad Pro through the keyboard for some extra juice 