Removing xrender from cairo's +quartz?

Hi all, I'm working on a Portfile for Shoes: whytheluckystiff It relies on the Quartz version of Cairo. However, installing Cairo with +atsui +quartz still insists on building xrender, which brings in all of X11. Any Cairo gurus know if that's really necessary? And if not, is there a clean way to remove that dependency from within the quartz variant? Or, should that be part of a (default) X11 variant? -- Ernie P.