Note the certification differences:
Normal category singles may be spin approved, but are not required to be. They will, however, for certification, have demonstrated recovery from a one turn spin in no more than one additional turn. Nothing says that this recovery has to be easy, just possible.
Utility category aircraft, if to be spin approved, are required to demonstrate recovery from more demanding spin conditions.
The forgoing shows the difference on the spinning categories approved for the 172 - normal vs utility.
Multi engined aircraft are not required to demonstrate spin compliance at all for certification, unless they are requesting spinning approval as a utility aircraft. I'm not aware of any examples of this. They are required to demonstrate single engined stalls, but if you're spinning a multi engined aircraft you are probably a test pilot for that flight.