Rated 3 out of 5 stars
This is in response to your comment about not wanting to create an "alternate interaction" (in response to my request for right mouse support)
Today, I needed to update the bookmark for http://sundaystreetssf.com/ with http://www.sundaystreetssf.com/ (FWIW, my bookmark is titled "Sunday Streets San Francisco"). Replace Bookmark reported "No related bookmarks found." The bookmark was there, of course! THIS is why I suggested adding the right mouse functionality from Update Bookmark. Over half the time that I try to use Replace Bookmark, I receive a "No related bookmarks found" and am forced to do a manual edit. It is no different than not having the extension at all. With the proposed "alternate interaction", your addon would be functional 100% of the time. Mo' betta IMO! :-)
It seems that "over half the time" you're trying to use this addon for purposes I didn't plan for (see description).
At the moment, like the description says, it only shows bookmarks from the same domain (including "www" part). But I could make it recognize subdomains.
Please post an issue here: https://github.com/dgutov/bmreplace/issues