Good video, and good question, as someone who has rebuilt a few transmissions and ordered Mazda parts, Its almost a crapshoot as to the quality and consistency of the new parts delivered. I have witnessed variations in hub springs, syncros that are to tight, and forks as you point out with different finishing.
Edit, I am not down on Mazda, at least they are providing the parts, this is more of a part supplier issue but just commenting that there have been some issues that are causing problems.