This was suppose to be a muscle growth animation but I decide to scratch that and make my muscle growth chart. As you can see the muscle expand not affect much to the height which will give more volume to the muscle and I think F is my limit, going more than that will look weird to me. The one and only way for me to make the muscle more bigger than F, I have to stretch out the body limbs so the muscle itself can growth more but as I mention moment ago, this muscle expand not affect much to the height and more focus giving more muscle volume or mass.

let me know what you think.