Edit URL when adding

Seems like a lot of webcomics have a feature where there's a URL that you hit to go to the latest page, but it redirects to a different URL that's a permalink to the latest (at that time) page. Unfortunately, this means that when adding the site to Today's Pages, you have to then go into the bookmarks to edit the URL to the one that does the redirecting.

It would be nice to have something like an advanced add interface, that lets you edit the URL before adding the bookmark.