> It's using 3-phase drone prop motors with no gear reduction.
If I'm understanding correctly, this is not accurate. The paper and the Github repository describe it as a "dual stage timing belt transmission with a 3:1 gear reduction on each stage".
Aw, you're right. We're still not there on tiny direct drive. I've seen direct drive robots with large "pancake" motors, and thought they were driving those little guys that way. But no. They still need a lot of reduction. I'm surprised that they bounce as well as they do while back-driving through 9:1