The author of TeledyN pointed out that the Find page did not search for alternate URLs.
I added that feature — first as a JOIN query which turned out to be very slow (since it has to do O(N*M) comparisons). I then changed that into two separate queries, one that matched all alternate URLs and another that matched regular URLs. This turned out to be much faster — O(N+M) comparisons. I wonder if it can be accomplish in on one “fast” query, though?