Top buds due to being so close to the light will never fully develop 9 times out of 10. Because they are so close, they will always be trying to produce, and this results in a more "head" high as opposed to body "stone". As they mature in cure, is when you see the change in high. Just thought I would add to your debate a couple of pages back!
ps. New undercurrent system is growing some trees just as I had expected!