Is there any study showing that the bone morphology changes on the hemiplegic side? I've read some studies and they only show changes in the bone density, the only study that looked into the morphology didn't find any difference, though it was a small sample as the researcher said himself.
Interesting topic. I suggest posing this question to Dr. Mike Mew directly on the Craniofacial Action Group. He should have the answer you looking for since he bases his argument for adult change heavily on this topic.
my story: http://www.aljabri.com/blog/my-story/
Instead of thinking about a neurological derangement for proof of what you're thinking of - think of the opposite, what if one side works better than the other (compared to worse with stroke victims)?
In tennis players, the forearms of the dominant side are visually measurably larger than the non-dominant side. Same DNA running through the body overall, but the body adapts to the load placed on it. This is the "epigenetic" view of bone dynamics, and is not widely agreed upon in the medical community. The medical community largely believes the "genetic" model - your bones grow, become a certain size/shape/length, and then stop.
https://biomechanics.stanford.edu/me337_10/projects/ducher05.pdf