Thank you. You probably already know this, but ThrustCurve shows the motor as certified. I actually purchased a TVC kit from BPS Space because I thought the motor was "cool." Hopefully, Joe at BPS is not upset about how this went down.
I agree about having a temperature limit. Is the NFPA limit intended to protect the rocket from damage, causing fires, or people getting hurt? That is, what is the reason for the limit?
Honestly, I don't know much about the construction of HP motors. I'm taking a class in a couple months and frankly wasn't that interested until I saw this problem with heat.
I've seen motors being static tested, and usually they are not in the kind of motor mount with a tube like you would typically see in a rocket. As most people know, paper or phenolic is a great insulator. So, heat would not dissipate rapidly after the burn. Also, I would think the temperature curve would rise abruptly at the end of the burn because the last of the propellant would provide some insulation. Well, unless it was an end-burner. What if the propellant grains were in a material that could be consumed but not as fervently? Or, 29mm motor enclosed in a 38 mm case?
So, what I'm suggesting is rather than changing the standards dramatically, mitigate the problem.