jj, I learned that (draw below anchor then lift to anchor) when I learned the NTS (rotational draw). It helps to get the lower trapezius and rhomboids engaged as far down in the back as possible.
In the NTS, it is called "drawing to the loading position" and it allows a deep (low) back engagement that can be set; then the lift to anchor keeps the back set and allows the references to be set the same each time.
Again, in the system I use, the string elbow should be on or inside the arrow line in the horizontal and ABOVE the arrow line in the vertical. I know that many "trad" shooters strive for the elbow in line with the arrow both vertically AND horizontally, but that breaks the straight line of the force vector coming from the bow. Lining up on that vector is a LITTLE more efficient than not being on it.
Arne