Stepper de-rating

I hope this is not off topic, tell me if it is.

I am wondering if all the stepper experts can advise and old servo
motor guy about the merits and problems of derating a stepper. I
understand why steppers dissipate power, there is always current flowing.

What would happen if one were to size a stepper at twice what the load
needed and ran it at half rated current. It seems it would have to
operate at a much lower temperature. If the increased rotational
inerita were not a problem, what else might be.

Thanks;

Ken