I understand the purpose, but I would question the precision.
When talking strictly about generating speed and "purposely braking", I think it's snake oil.
I feel its helpful to those without enough pivot lag.. and have a shoulder the leads too far into the swing which would cause the person to look like they are bent over in the finish, or staying in their forward tilt whatever you want to call it...its a way to fix this...not necessarily a percision move but taking someone from one end of the spectrum to the other imop