I have seen some people asking that Autofade was not only for Zone out, as they then cant use it in the ‘mainroom’…And if you dont want to route the Zone out to one of the Line In’s on the Prime 4, and end up locking 2 channels down.
What if you use a small PA mixer between the P4 and your speakers, so you can route the Zone out to the same speakers as your master out? Line 1 = P4 master out and Line 2 = Zone play
(I know its more equipment, but like I say, just an idea, and probably a affordable workaround)
Best regards Engell