Yes, I'm talking about that separation part. Interestingly enough, I have in front of me the Bandai YF-29 Alto custom and the Yamato VF-19 Kai and the Bandai part is in comparison at least as thick as the Yamato one, if not even thicker.
Anyway, I had never paid much attention to that detail in my VF-19's until you and others mentioned it; so although line art accuracy is always preferable, this detail doesn't bother me too much.