Especially when stressing of muscles and joints are involved, you are always ahead of the game if any necessary motion of the body is done within the parameters of natural physical action/flexing.

Try pulling to the "under chin" anchor, and then to the side of the face/jaw anchor. Notice which anchor puts less stress on your drawing hand, wrist, and arm, and which anchor allows a smoother movement of the arm. I, at times, do use a sight pin on my recurves and still use the face/jaw anchor.

When all is said and done, the best anchor is an individual choice, dependant upon which anchor provides the best shooting for the person.