So what if the load for any reason keeps drawing current until the 20 amp breaker kicks off would this not be to late(20 amps) for the load(more damage) rather than putting on a 15 amp circuit(less damage)which is closer to the load 10 amps.
You seem to be under the illusion that your panel circuit breaker is there to protect any device you plug into that circuit. It is not. It's there to protect the wiring of that circuit, the power panel, and your home. Devices which require individual protection will have built in fuses or circuit breakers.