I maintain that the pitch clock is a solution desperately in search of a problem. Rule 6.02 specifically states that batters must keep one foot in the box at all times. The umpires simply refuse to enforce it.I submit this for your perusal and further comment.
MLB may finally have a popular rule change with its new pitch clock
Crack down on batters tapping dirt from their cleats and scratching their nuts after every pitch, and bingo, pace of play is fixed.