Would be nice to get support for multiple hardware input and output channels. My use case would be to use one audio out channel from an interface for normal output and one output from an usb adapter for normal output + metronome. I think this should work now with audiobus haven't tried it. At least my setup was working with Loopy HD, AUM and audiobus.

Would be nice to have the same for input. But I think the iPad can just use one interface at the same time. At least with Every app I tried so far - Loopy HD, audiobus, AUM and of course your loopy pro app - when I connected a second interface it was never detected. Seems like Just the first connected interface is always considered/detected.