[D11] Alters fade to be frame based rather than time based as the loading screen blocks the main thread meaning the fades would sometimes fade a little then completely cut depending how much time the main thread was blocked for. Changing volumes from either FixedUpdate, OnAudioFilterRead or even on a thread does not work as the Unity API is not thread safe! Yay! The upshot of this is that fades sometimes take a bit longer but they are always mostly smooth... bar a few little pauses but its not too noticable.