Here's a photo of a blue enamel 5177bb, mine.
It has interior angles and, obviously to an acute observer, post-dates the video Tim used for a screenshot which uses a prototype model and came out with the introduction of the blue enamel 5177.
I'm not sure why this is so hard for you, but here it is again: Tim made a sweeping argument with an easily falsifiable example: That Breguet had changed its manufacture process for a specific in-production model, the 5177, and this change removed all internal angles for every piece of this model going forward. The time given was with the introduction of the blue enamel dial 5177, which was when the PR vid used for evidence was produced. The picture I've attached of a production blue enamel 5177 from an owner, me, disproves that, and further Breguet itself went above and beyond to answer all concerns, including videos, and provided pictures of newly produced movements.
Breguet also, very reasonably, admits that there may be variations in hand finishing. That's another thing someone who read the opening post would know. I'm starting to feel sorry for you, maybe give up. Tim ragequit watchprosite a few years ago. Usually, I would mourn the loss of a longtime poster, but I'm not so sure of the loss this time. Spreading disinformation isn't useful for collectors, please stop.