Sorry, chas. I just wasn't expecting that line from you, of all people! Personally, I don't want to sound like Jimmy, or Claudia or Joey on a B3. I want to sound like ME on a B3!
Currently, I sound like me on a G70!

It was this line "I think 90% of the organ voices available on today's TOTL synths, including arrangers, are more than adequate when used in an ensemble setting" that set me off. Statically, maybe yes, you can get away with them. But if you use the Leslie dynamically they immediately fall apart, and sound, even in an ensemble setting, like the synths they are. Just like, even if you voice a brass section perfectly, and phrase perfectly, an unrealistic brass sound will shoot you in the foot every time. At least, to the trained ear. And, let's face it, realism is what we ALL are shooting for with arrangers, otherwise we'd be on synths!
Back to Bernie... That IS an outstanding Leslie sim, best I think I've heard yet. Just mad I can't use it, because I'm not willing to give up all my effects for just the one sound.

I'm surprised that you haven't managed to get the K2661 to use the Ventilator without interfering with the other sounds. I have a K2500 with KDFX, and it is possible to route any sound, WITH its' associated effects to a separate pair of outputs, run it through an external processor, AND return it to the main mix (if you are perverse enough to be determined to do that!) of the Kurzweil using Live Mode and the audio inputs...
Mind you, why even bother with that last step if you carry a small mixer pre-monitoring?
If I had a Ventilator, that's how I would be dealing with the KB3 mode, anyway... Turn off the Leslie sim in the K (but leave the Vib/Chor on) and route to a separate output. Job done! I used to do that with my Motion Sound all the time.