Currently, the engine only allows for up to 4 different holding points, which in the past were made for weapon/shield use. But when it comes down to it, allowing for more holding points could allow for some interesting sprite ideas; like altering the limbs/body of a character, or adding an accessory.
Although that alone could be achieved through the sprite editor, by using holding points you could set things up to alter a sprite across all of its poses, and therefore greatly reducing your workload!
More Holding Points