Strange... My MIDI controllers all can send MIDI notes via knobs if I so desire, but for a device to play notes when receiving CC's is a new one for me.
The Keystep (and the BSP) send 50, 51 and 54 by default from start, stop and record respectively, IIRC. I've changed them all to transmit CC124 as I have no need for omni mode, so transmitting an "omni mode off" message interferes with my devices none. CC50 being sent every time I pressed play was causing three of my Waldorf synths to jump to the max level for their filter cut-offs. Very disruptive it was.