Hi
Two suggestions for the great Keystep :
1/ Using a fixed Midi Note (on a chosen channel) to act as a clock source for both arp and seq, like the analog sync in, except one won't need to use an analogue drum machine just to enjoy this feature when he is mainly using Midi gear.
2/ Being able to input notes for the arp and sequencer from an external Midi Keyboard via the Midi in port (yes, sometimes the 2 + 1/2 size keyboard can be short when doing polyphonic sequencing).