Even if "not cleared to spin" surely an aircraft should be recoverable if it does?
The "not cleared" is presumably because, for one or many good reasons, it's not a good idea.
But an aircraft that will kill if spun, intentionally or not, is hardly airworthy, I would have thought.
I did try to spin a Cherokee 140, some years ago, but could not achieve more than a very steep spiral dive, really, even by slowing to almost the onset of a stall, then chopping the power, heaving back hard with the elevator and giving it full rudder, and holding that pose for a while. The problem was then the speed which increased rapidly in the spiral dive that eventually developed, and resuming level flight before it increased any more, without breaking something. I think there was a spring connection between rudder and aileron to make it as much like a car as possible, which didn't help.
Is a Warrior like that?