Changing arm slots for different pitches?

Ok, so before I have my son completely scrap the low 3/4 arm slot change i’d like to pose a question. What are thoughts on keeping his arm slot at the high 3/4 on fastballs, and curveballs but throwing his cutter/slider, and changeup at a low 3/4 slot. OR should I have him keep trying to throw everything at low 3/4 in hopes that it will grow on him and he can adjust and get used to it and throw everything from that slot?? Just looking for good suggestions because i don’t want us to “waste” a good portion of his off season. Thanks

You want to make things easier for the hitters, go ahead. But I don’t think either you or he want that. You want to have him make the most of what he has and can do, and that means sticking with the low 3/4 slot (which is as close to sidearm as one can get) and learning to throw everything from that slot, learning to change speeds on his pitches (something Ed Lopat told me ages ago)—and being aware that this particular armslot is easier on the arm and shoulder than the high 3/4 or overhand. About the only pitcher I know of who got away with throwing different arm slots was Orlando (el Duque) Hernandez, who did it successfully for some years.

Zita, Coney used to do it as well

Yes, I El duque used to do it, and also Cone, witch is why I don’t think its not unheard of or a “terrible” thought. Of course those guys were both established MLB pitchers, but at the same time I’m sure they had to start somewhere. But it was just a thought, like I said he wanted to try the low 3/4 and the first time he tried it he said it didn’t feel comfortable so initially i said well don’t do it then, but I’m wondering if I should have him continue to try and maybe he will get the hang of it and will become comfortable.