Hello Peter, after thinking thru my problem of not having midi control of multi output volumes, I think I have a work around.
Without going into why I need midi volume let me say that if I were to use 2 separate iOS devices, could I have the desired remedy of being able to take center stage without all of the cables?
The master iPad with multi out interface or mixer out on the side of the stage being controlled with Bluetooth foot controller and a slave iPad (WiFi and working on battery) on front mic for lyrics.
Can this work properly? Do you forsee any problems with connectivity between the 3 devices?
Stan