Here is my reasoning.I can certainly believe that, Helmut. I mean, when you add a shaft hanging out of the engine then you have to design for all kinds of extra force that you can omit with the ES.
I really wouldn't doubt that the ES models actually cost less to build, or at least not any extra in terms of pure parts alone, but they sell for more because of the perceived extra cost, or they are recouping design costs.
But anyway, I certainly wouldn't doubt that it would cause more problems, and you would probably be better off to sell the ES and just buy an S.
Notice the two different spindles one labeled "30" and the other labeled "10". "30" is used in the ES models while "10" is used in the S models. All other parts in that entire selection are the same for the ES and S.