Interesting approach. As I understand it they are offloading the calculations onto a Raspberry Pi, but leaving the Arduino in charge of the time-sensitive stepper driver stuff. All the advantages of a Smoothieboard without the cost?
I’ve been following the development and discussion over Klipper, I agree it’s a promising firmware and hopefully will have time to play with it soon. If you interested I’ll happily bring one of my delta and we could play around during one of the 3d evening also hopefully starting in January
In regards to micro stepping I highly recommend this microstepping-myths it explain pretty well where the problem escalate
This is why when building an high end (those are usually a bit more expensive) machine stepper motor with 0.9 degree steps are better than 1.8 degree