Voxfan, under Drive, there is Rotary A and Rotary B with a depth adjustment only, controls drive, no rate control for speed. Rotary B is a better B3 sounding Leslie. In Effects, there is a simple rotary option that is the same as Rotary A in the drive section. Effects does have a rate knob, and at rate 64, seems to be the default used in Drive. With Rotary Speed on high, it does sound better at a rate of about 30 to 35. The problem would be that rate is to slow when changing back to slow speed, not to even mention again that it is the weaker of the 2 rotary options.
Overall, the H patches, for Hammond, is the weakest part of the board. Maybe used at a practice or on a 3 lowest drawbars and on slow rotary only song. If you have an Ipad, or Iphone, with interface built in so no worrying about audio out, you can map all the sliders and knobs to any CC control, and even separate lower and upper drawbar CC numbers. For any buttons, except for Rotary speed which is #9, it still uses Sysex, so you would need a translator like Keystage if you had to have the exact same buttons control what it says. An example for B3X, there are 18 non drawbar CC sliders and knobs and 2 foot pedal CC#2 f you don't want to go down the Keystage route to control Vib/Chr and Pec and the other midi controllers listed.