Could this have to do with the lack of involvement from his lower half? I remember watching his delivery after we drafted him and being concerned about that. I can't find the post but I'm sure I said something about it at the time.
Regardless, if it ain't broke, don't fix it. I hope we leave him alone and let him develop with what's been working for him. If he proves that he can't hold velocity or is getting hurt, then maybe look into mechanical adjustments.