Carl, the whole concept is to keep the driver blade bottomed out in the slot tight enough that the only thing the screw can do is turn- - - -no way for the driver to cam itself out of the slot and bollux it up. Once the slot is damaged, about the only option then is to drill it out. Some of those screws can be TIGHT! We used a smaller-scale but similar tool to remove stubborn screws for access panels on airplanes back when I was in the USAF.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!