I had this tool at one of the shops I worked at, used it once. Waste of time.
As you turn the eccentric piston you will notice it moves in and out as you shift from forward-neutral-reverse. When it's at the most in (half way between forward or reverse and neutral) that's were to do the shimming.
Use the procedure for the type 1 or type 2 shift mechanism. They shim the same as your DP-A