I hone the overall shape (although I was heavily influenced by US/Aussie drumbots), Dave comes along and makes it better, then I come along and copy his improvements
But yeah, not a huge scope for major differences, Touro aside.

Wheel OD is 125mm, running on a 5S lipo, 16:1 gearboxes and still tossing up between 775 and 550 motors. The CAD is with 775 motors but there's literally just 5mm of space between the ends of the cans. I don't know how easy it is to pick up spare 775s over here compared to 550s so that could factor into things.

I also envisaged just being able to slide the motor/gearbox out through the cutout in the side, hence why the lack of space in the middle wouldn't be a problem, but now that you've drawn my attention to it, I've realised that the motors are larger than the surface area of the gearbox and wouldn't fit through the cutout. 550s would though. Hmm, deliberations!