A two plane swing requires you to start your downswing with a hip bump forward and then arms pulling down, which relies a lot on having good timing
Golfers who have a problem hitting the ball too low usually take too short a backswing or have too much lag in their swing which takes loft off of the club at impact and drives the ball lower than desired
This putting grip is mostly used with a straight back and straight through putting style and eliminates rotation in the follow through