You’re absolutely right. I was referring specifically to the possibility of modulating the Play parameters using MIDI data generated by a DAW or external instruments and controllers. This will allow the use of external LFO and other types of modulation.
The midi implementation is available on all hardware devices that work with midi data in one way or another. Play can transmit midi data, but only accept sheet music. It is not entirely clear why it is impossible to specify in the code the binding of Play controls to CC messages. A year ago, I wrote an appeal to support about this, to which I received a response that it might appear in the future. That’s why I’ve been hoping for this all along.