The correct draw length has nothing to do with your loop. It has to do with your body dimensions and your form. That determines your draw length. No matter how you look at it my arm is a set distance away from my vertebrae. It will not change. The distance the bow string is drawn has to be correct in order for my head which is attached to my vertebrae to stay in alignment. If the draw length of the bow is too long, my head must compensate by leaning or turning back. If it is too short, it must compensate by leaning forward. Draw length allows for you to be in perfect vertical alignment while your loop allows for your arms to be in perfect horizontal alignment.

I have a 28" draw. When I draw a bow with a perfect 28" draw my head and vertebrae will be in perfect alignment every time. I won't have to lean back or forward. If I go to 27.5" I have to lean slightly into the string. If I have a 28.5" draw I have to lean or turn slightly back. Now at 28" if I add a 2" loop to my string in order to get my arm positioning and hand anchor correct I still have a 28" draw that hasn't changed my vertical body alignment. I don't however have a 30" draw. If that is what you are saying that is going to confuse people.