Ed,
I've tested the point of no return for a Nacra 5.2 and I can tell you that, depending on crew quickness, and the skipper's neck strength, a healing angle of 90 degrees can be brought back. The skipper needs the neck strength because he's hiking out on the top hull while the crew has his leg around his neck hiking (rather dangling) out further. The drawback here is that when the sail finally inverts and lifts the boat back upright (whew), you quickly find yourself on the wrong side of the boat after an inadvertant tack and now you're blowing bubbles laughing in the water....point returned but a bit too far (and no balls involved).