I thnk what Kimbo is saying is correct, about ball placement. You can hold the ball lower, but if you push it up/higher in your pushaway, you're defeating the purpose.
So, on the pushaway, you will have to place the ball lower at the extension of your arm/pushaway. When your arm/pushaway is extended and the ball is lower, your backswing won't be as high, thus, a slower ball speed.
Holding the ball lower, lower pushaway, with the shortening of your steps and approach distance, will all need to be in sync to have proper timing. You cannot do one thing with out doing the others and still be in time. =:^D