Son doesn't care who calls the pitches or what pitch is called, he is ready to throw before the batter gets in the box. He just wants the sign down quick, because he is coming as soon as he sees the sign. Changes a little with runners on, of course.
Most teams have their batter get in the box with their back hand up. Coach calls the pitches at our school. First game or so was a little off tempo. But the coach adjusted, gets signs in quick now. Son has stayed on rhythm last couple of games.