you are correct, master volume for that page to be replaced by the current zones volume control
it would look cleaner than having 5 sets of volume controls on the media player page, or the music page.
cause i have 5 zones, it would be very cluttered.
i will take some screenies tonight and add them to this post.
the volume control here should be the current zone(bottom left of image)
this volume should be the current zone
(this is an older picture, no volume control is here, from your gallery page)
currently i have to keep opening this page to edit volume