If there is a way to do it, I don't know how. I will search the RTI forums...

You can patch it by using the zone level driver command in every source selection. Kind of a pain to find the right levels at the beginning, but it you often sell the same stuff, you will be able to achieve it whitin minutes on a new install...

Might not be a good solution, but this what we've learned to do when installing a Speakercraft MZC...