Electric Motor Design

I think the question is

"What are the differences between a standard three phase motor and a three phase motor designed for a high start/stop duty cycle?"

Yes you are right, But from manufacturing point of view.

Usually more iron to dissipate the heat created by high duty cycles. Most people just over size the motor however.

My doubt for above as more iron, since more iron means more hysterasis and eddy current losses and more heat on account there of.

Usually cooling in made better by incrasingframe size and higher insualtion to take care of hot to hot start up.

Do you mean enlarged motor enclosure area to act as a bigger heatsink to dissipate heat faster?

The area is increased so that the heat disipiation becomes ditributed through more area. The Stator inside fins are also being provided for the same purpose