I would like to be able to adjust the volume of the bass and treble staves in the mixer, but I haven't found the key or shortcut to decouple the two tracks. The faders continue to move together.
Can you not adjust volume between staves with dynamics? You can't split treble and bass staves because they belong to the same instrument. You could of course manufacture a double staff piano from two single staff pianos, tho' I can't figure out a way of connecting the two staves with a single brace.