Brian,
For what it is worth, your draw length 3 under or split should be the SAME! Your pictures show a pretty good position BUT as I say, it should be the same if you are shooting split. Look at the string in your pictures -- it is in front of your eye and if you were wearing glasses, it would touch the center of the lens.
Too many seem to think that draw length is the end all be all of shooting BUT good positioning (alignment and form) is FAR more important.
Very frankly, the ONLY difference between 3 under or split is the "aiming" picture it gives. Form remains the same AND release remains the same.
Arne