I want to set Audio Output Device to "No Output Device" permanently because I don't use Avenue for audio, but it resets my Audio Output Device to my default Windows audio device whenever an audio device is added or removed. Specifically in my case, this is when I either turn on or off the NVIDIA Broadcast App virtual audio device.
If I set Audio Output to "No Output Device", I see no reason why it shouldn't stay that way until I explicitly change it.