Audio can't be controlled by essential graphics
There doesn't seem to be any way to make audio editable in a mogrt, would be great to be able to do things like link audio levels to a checkbox to make it possible to enable/disable through the Essential Properties etc.
Currently manipulating audio with Essential Properties appears to be impossible
Henk van der Velden commented
I've been having the same issue, tried check boxes, sliders and a drop down control, but the audio levels don't change when using the Essential Properties.