I just got my Keystep and one of the things I was very excited about was the Rate Knob. Unfortunately it doesn't seem to do anything when the clock is coming from the DAW via USB. Of course, preserving its functionality when synced to a DAW is not straightforward, given the conflict between "free tempo" and the DAW's own tempo. But, in my opinion, it's a very interesting challenge which could give birth to a great design, if you cope with it in a clever way. For instance: the "zero" position of the knob could be the present ARP/SEQ rate, and turning it would increase the rate. Regardless of any sync. But, when going back to zero, the sync is restored (the trigger should wait for the next beat).
It's just an idea, but it's kind of sad seeing a knob unused, especially on such a minimal design.