You should be able to assign the volume buttons to pedal actions, but currently, my app is not consuming the button press, so it's passed back to the OS which will then still adjust the volume. I have a fix in place so that in the next update, if you press the volume button, it will just perform the action you want without adjusting the tablet volume. Be aware that this means you won't be able to adjust your tablet volume with those buttons while using MS Pro. If you want to adjust the media player volume, you'll have to do it using the volume control on the player itself.
Mike
Mike