lag,
I used it when I first learned that wristcock was a vertical motion, and took it to mean vertical to the ground and not to the plane. A is very difficult with the longer clubs, especially the driver. I can get my max distance with a 9 iron using A, but it's effectiveness decreases for me on up through the mid and long irons, and woods. On the Chuck Evans forum, I used to ask about certain topics in the framework of 10-6-D, but never got any responses from anyone, including the top experts like Chuck, so I assume that few are familiar with it.
Phil Rodgers, although a short game specialist and not, I believe, TGM trained, has talked about a full swing method that sounded a lot like A. He said that you should get the club vertical on the backswing and back to vertical on the follow through. The idea was that when the club is vertical, it feels as light as possible, so to execute the swing you just always keep the club as light as possible. This is sounds like an "anti pressure point" concept. I believe that one time phenom, Sam Randolph, used this swing. Hitter Craig Stadler may be using this also. Perhaps Scott Hoch among the Swingers. Anyone who is "ultra-steep", and vertical is about as ultra as it gets.
As for variation B, although I have seen some tour players do this, very few tour players(or any one else for that matter) set up with truly vertical arms, which gives very low hands and maximum #3 accumulator, and even fewer still keep them that low through Impact. Perhaps Jim Furyk would be the closest example of the current tour players. From the past, Don January might be an example. If I come across a good example, I'll post a link.