Then an API to feed that to some code which forces the swap dynamically to use the new device, assuming you want to do that without forcing a restart.
If you mean something like this:
Audio::IAudioMixerPlatformInterface* PlatformMixer = MixerDevice->GetAudioMixerPlatform();
PlatformMixer->OpenAudioStream(OpenStreamParams)
I’ve done that, with the same result. Audio cuts off then resumes on the same default device. I tried that with some combinations of CloseAudioStream() TeardownHardware() PostInitializeHardware() StartAudioStream().
I’m not sure what the proper procedure with all those steps should be and which ones are or aren’t necessary.