Never seen the grip used. We train on indexing and thumbs. Just never seen the off hadn finger tips touching in between the strong hand fingers. My fingers are to big to achieve that, especially with a mag well installed. Nice shooting.
I bet your hands aren't any bigger than mine and thats the gip I use other than my off hand fingers are on top not in between. Seriously my Commander sized 1911 looks like a sub-compact 9mm in my hands. After learning that grip from TDSA I can keep my groups crazy tight.