I would gladly purchase a Rotary Speaker simulator effect that responds to Midi CC to adjust the speed.
But I'm probably the only person that would
I had switched to a laptop running Kontakt 5 for live performances - last night after a short break Kontakt stopped responding to midi (who knows why)
Switching back to my Note3 with AEM allowed me to keep playing - NO ONE NOTICE THE DIFFERENCE EXCEPT ME and the ONLY thing I missed was the Leslie Speed Control
PLEASE add this effect to your Add On choices