Because you are talking about the Audya Drawbars simulation, I have a question.

On the SD2 or SD4 (mayb on audya too?) if you send a controller 0 bank 67, you get a drawbar sound.

You can use a drawbar sound on many channels together. SO you can for example play a drawbar sound for the left sound and another drawbar sound for the right hand.

The problem, is that when you change a drawbar value, it change for both channels together

Do you think it's a Ketron bug or it's a limitation of the Ketron drawbars engine, so drawbars are global for all the channels together?