Hello there,  I think someone here is on the right track.  If you own
a MIDI-controlled organ and someone is asking you for the "key-count"
(e.g., on the application to an organ festival) just place a "N/A"
there.

And (/or) instead you replace it with the phrase that Bob Essex used,
"XYZ active MIDI outputs", which is an accurate description of what is
happening in your organ.

I. Krause
Burnaby, BC, Canada