RemoteIO Airplay Output Passes Through

Question

To prove the concept, I'm trying to bring an iDevice microphone over Airplay. I modified the AurioTouch code to provide a pass, and it works fine using mirroring from 4S / iPad 2 to Apple TV.

However, when I try to use standard Airplay, either with iPhone 4 / iPad 1 or Express Express, the audio outputs from the device’s speaker, even if the Airplay device is selected using either the system’s exit route selector or MPVolumeView in my application.

Is there anything I need to do to enable Airplay in my AudioUnit? According to the documentation:

AirPlay support is built into the AV Foundation and the Core Core family. Any audio content that you play using these frameworks automatically gets the right to distribute AirPlay. After the user wants to play audio using AirPlay, he is automatically routed by the system.

But I do not seem to feel any joy.