http://gentoo.petteriraty.eu/stable.rss
I updated the Stable Candidates bug feed to have open bug numbers for ${CATEGORY}/${PN} and ${PN}. It will of course be a little behind actual bugzilla data as the feed is updated daily but that’s good enough in my opinion. I think the next item for the feed is to add a link you can use to file the actual bug. That should make it dead simple for you to file stable bugs on stuff you use.