Let us not forget as we discuss temperatures that if the hitch is getting hot enough to melt polyester, our ropes are polyester and they're getting hot too.
Probably not so much of a problem when you're moving, but what happens when that hitch is near the melting point of polyester and you stop?
A buddy has glazed several ropes. That's an indication that not only is the friction device, be it mechanical or 'software', getting hot, but it's transferring the heat to the rope while it is in motion.
The point? We may have a high temp split-tail, but we still have a polyester rope and heat does transfer to it, even when we are in motion. Imagine the heat build up at a specific point on the rope when we stop.