This sounds interesting. And there are perhaps more than one way to skin this cat. Plenty of flippers out on tour.
You can flip without ruining your lag pressure. It can be the same rate and timing of overtaking by the club, but with different hinge action. For instance take a very strong double action grip and the hinge action and accumulator#2 lag gets married. You can hit the ball a long way doing this but it becomes more difficult to feel the swing and control the lag.
But the TGM way seems like the best way to me. So this is not worth losing any sleep over.
Also be aware of semantic differences. Flipping doesn't always mean the same outside TGM as inside.
Funny . . . dude this type of "flipping" is in an entirely different context . . . as in "flipping" flop or out . . .