NOW,for the twist about parallax and shooting from a stand.
Most of us agree we shoot for the distance from the base of the tree.This is because of gravity but parallax is separate from gravity and you must consider the height you are in the tree for it.Meaning,if you are shooting from 25 feet up this is 8.333 yards,meaning you no longer have a parallax issue if your parallax crosses like most between 5-7 yards.So a shot at 5 yards or less does not really need to use the 40 yard pin if the animal is 3 yards from the base of the tree.
This is why you must practice these scenarios.I know this will come with disagreement and that is why I refrained from posting sooner but it is what it is.