[Al Skierkiewicz]

Fenix,
A couple of things to think about.
300 degrees on the outside of a CIM indicates that the internal temperature exceeds that by quite a bit. I am confidant that the failure point of the insulation on the internal wiring of the motor is being reached by those temps. Please double check that figure. The high temps indicate excessive electrical usage as well indicating that the motors are being operated outside recommended practice.
There is a condition called 'thermal runaway' in electronics. This is a condition where the temperature reaches a point where the electronics have a mind of their own and cease operating with any control. Since the Jag internals (or any other electronic device) suffers from this effect, catastrophic failure of the device is likely should these temperatures be reached.
Acrylic is considered a hazard on FRC robots and therefore fits under that category in the rules as being a banned material under R08.