For those that are interested I have this working.

I have put together a setup that is a split keyboard KB3/VASTB3 setup utilizing the double leslie. This setup provides the ability to have independent drawbar control of both the KB3 organ and the VASTB3 with the use of the SW button to switch between the organs so that the 9 sliders of PC3 will adjust the drawbars of either the KB3 organ and the VASTB3 organ by simply employing the SW switch. I would like to give shout outs to both Jean at Kurzweil Technical as well as Dave Weiser with their efforts in this. Jean was instrumental in getting the drawbar control to work independently between the KB3 organ and the VAST B3 organ and Dave was instrumental in getting the double leslie to work with the sustain pedal for slow/fast and applied as an AUX FX so that the double leslie can work with the both organ programs in the setup.

Here are the particulars of the setup:

• KB3 organ on the top end of the keybed (program Upper KB3), VAST B3 organ on bottom end (program Lower VASTB3) of the keybed, split point at C4 (adjustable within the setup)
• Independent drawbar control of both the KB3 organ and the VAST B3 organ using the one set of sliders on the PC3. The drawbar ‘switching’ is done through the use of the SW switch. When the SW switch is unlit (default) the 9 sliders on the PC3 control the KB3 drawbars; when the SW switch is engaged (switch is lit) the 9 sliders control the VAST B3 drawbars
• From a program perspective I have defaulted the C/V off and the percussion off (both of these are adjustable and can be defaulted to whatever you’d like. Adjust the program Upper KB3 to do this).
• At this time C/V is NOT available on the VAST B3 lower layer even when C/V is engaged. C/V presently will only work on the KB3 organ
• The double leslie is triggered slow/fast (defaulted slow) by the sustain pedal so that both hands are free to play the keyboard and no alternative pedal needs to be introduced. The rotary on/off button is disengaged because of the reassignment to the sustain pedal using a FUN. To reassign the slow/fast to the rotary slow/fast button rather than the sustain pedal, edit the FX chain (Aux effect) in the “Upper KB3” program, then go to FXFun page and change the sustain pedal to “Legato SW”. The rotary slow/fast button will now change speeds when it is double clicked.
• Within the setup are two programs called upper KB3, Lower VAST B3. The KB3 is defaulted to 888000000 and the lower is defaulted to 308400000. Both defaults are adjustable by going into each program and changing the default.
• One effects chain called 'Double Leslie' saved as a user effect and is used as an aux effect so that it can be applied to both the KB3 and VAST B3 programs at the same time.