Now,to your question, if the shooter has the draw length he wants and he changes the loop length,something has to change.Anchors CAN NOT just be adjusted back because the body positions are not correct(elbow slotting).
That's a matter of "choice". But I agree....SOMETHING has to change. We just disagree on what that is.
Let me ask you a yes/no question.....
If you have determined your proper anchor position for the release aid you plan to use......and you know which bow you want to shoot.....AND you have determined the CORRECT DL for your chosen style.......
.....Now you want to change your loop for this EXACT setup.
Will your DL change if you alter your loop length (if you do not change anything else)?
Yes or no?
For you to shoot this setup....I agree....something will have to change. But that'll be your anchor points (assuming, again, you maintain proper fitting).
Using your "logic", an archer could shoot a 25" DL and a really long loop....and have the loop affect his DL. I'm a little more realistic than that. Is he still properly fitted?