I had the same problem, I needed to find variations on a track in a client's library. I came up with a workable, if messy and slow solution, which was to search the library for the first (best) match, then rebuild the library without that track, and search again. Repeat until no matches are returned, or you hit (say) a ten matches. Did you ever file a feature request? It feels like it should be possible for the library to return multiple matches.