I jut thought it was odd that they had a second d-loop rather than just using one and lowering the anchor point. All they are doing is string walking with a release.
For some of the longer 3D shoots I always used an adjustable sight and for extra long shots I would use the bottom of the sight frame as a reference point. Some places like to set extra large targets 100+ yards out in a field to mess with your head and throw off your yardage calculator..
I don't recall having issues with when I shot some of the field leagues but I do not recall the max distance our club had.