Just an vague idea but I wonder if using zebra (or similar search

utilities) for authorities is really a good idea. They are great for
general bib search where you want to find more, even unexpected results.
But with authorities your concern is to find a specific record as such
the search facilities in a standard db are probably more useful. Just
because a tool works well in one context it does not mean its the best
in another (pick your favourite hammers & scredrivers analogy)