The C172 is capable of doing stall turns...whether or not they are designed to fly such a manoeuvrer is another issue...I have seen many done during mustering ops and they have handled well. Don't recommend trying them without known how to do them properly. And if you do, do it in a plane built for aero’s. Also the manufacture won’t take any responsibility if something happens.
My first employment in aviation was flying ag--crop dusting, right after high school. I've done a lot of low level maneuvering work, from chasing animals to firefighting to ag work, and there is never a call for hammer head turns (especially in aircraft not designed for it). I've seen more than a few pilots do it too, but inevitably they're the ones destined for tragedy at some point. It's just not necessary. Pushing any airplane beyond it's design and certification isn't necessary, and is always a bad idea.
The manufacturer isn't going to take responsibility anyway...that should never be the criteria in determining how to act in the airplane. Staying within the certification and legal limitations of the airplane, and the conservative safety boundaries of the airplane should be the yardstick.
Hotdogging and cowboy flying has no place in the cockpit.