If set to 1, will allow au.IsUsingAudioMixer to swap out the audio engine, even if there are systems in the world currently using the audio engine.0: disable usage of au.IsUsingAudioMixer when the audio device is actively in use, 1: enable usage of au.IsUsingAudioMixer.
Usage
au.AllowUnsafeAudioMixerToggling [value]
Set via the console (~) or in DefaultEngine.ini / DefaultGame.ini.