variants, deps and upgrades

Hi I'm doing some tests with gtk-quartz. Many hours of genuine delight garanteed. Now, gtk-quartz does not need Xft2 and xrender. So I made the quartz variant remove those deps. But "port upgrade" will try to install them anyway. So I thought of this. I could make quartz variants for those ports to make them install barely a receipt. Some sort of stub. But it seems like a cheesy solution to me. Any advice ? thanks yves