Reset the Mixer Panel back to all 0's (Or, back to "new score" defaults?)

Hello all... I've been hunting for a way to reset the Musescore Studio 4.4 Sound Mixer Panel, for a while now... am I blind or is there just simply no one-click option for this desired action?

What I'm trying to do, more specifically, is to reset all of the individual instrument audio modifications (such as volume level, Panning L-R, AUX Channel changes, Master Volume Settings etc....) back to all 0's, and default MuseReverb Aux Settings, as if the score were just created, blank, and nothing was altered.

Anyone have any insight on how this is done? I've skimmed through the Handbook, and was unsuccessful in finding any solution to this.