What are the advantages of padding the poll?

If your headpiece is well cushioned on the bridle, and many are nowadays, this negates the need. However, if not and you are employing the poll with a loose or fixed lever action design of bit then it is beneficial to change to an ergonomic headpiece that is cut away from the ears and offers a greater degree of pressure distribution. The poll is a very sensitive area and poll sensitivity may not manifest itself straight away when the bit has been changed, so you may not make the association with subsequent evasions such as head tossing or head shaking.