From the time he started pitching, my son has always been one to work inside. His philosophy is that he doesn't care where the batter is - he is throwing to the target the catcher gives him. That's his job. He can't control if anything gets between him and the target - be it a bat, a body part, or a dove.
Pitchers need to throw to the mitt. Do that and it is irrelevant where the batter is.