The Haskell (or some lazy languages) translation should be a separate 2 kyu problem. It is not fair as the same algorithm in other languages would have passed will get time out in Haskell, and to pass the test we need to dig deeper in the patterns than the other languages.

For a kyu 3 kata, I think it deserves a hint in the description. Or make it a kyu 2 and add the same kind of "advanced" tests to the other languages.