These tools are designed to be operated by hand - just a few turns at most. It would be very easy to overdo it using a machine. Or suddenly get a lot of tool "chatter" damage.
BTW if you fit it so that it is slightly tight between pivots, then use a soft punch to tap the key towards the post with a "dolly" behind the post, it will shape your hole to better fit the particular screw, hence less future wear.