Best way to know, ask Charlie from Novak, cause I think you can turn your EPA down as much as you want and your ESC will not get any hotter.
With brushed motors, they send pulses to the FET's, less pulses or smaller active on for the FET causes the motor to go slower (average vltage is lower). Dunno about brushless though (School has been too long ago)
If the ESC is burning 20% heat when you're at 80% throttle -> with this way of thinking you would SHORT the battery when you dont give any throttle at all....
I say, just turn down the epa (if I do am wrong, it will thermal without leaving damage)