The master mode on the KN7000 simply means that it is the controller. I can swith local(KB) sounds off and on per part if I choose. Hence I can layer or hear either. I did get the USB to work. As Sturgeon says, you can get Audio and midi.

This thing is both simple and deep. but I know it is a road warrior. and will get it together eventually.

The tech support is tremendous, and have helped a lot.
Bernie