Occasionally when I am the first to cast a "Close as duplicate"-vote, and search for a target Q&A to reference, it happens that I shortly after that stumble over another Q&A that would actually be a better fit. In these cases I really miss the ability to edit my duplicate-vote to reference that other Q&A instead, which is a pity since I think it's common for following voters to perhaps not go and read the Q&A, but just vote for the same one as the first voter.
I saw the feature request Improve tools for closing as duplicate, which would probably decrease (if not completely remove) this "problem", so if that one would be implemented this one would not be of interest anylonger, I think.
