It's so cool to get a tour like this, fascinating stuff.
The part at 13:30 seems to be some really valuable knowledge, when he says: if you are not occasionally adding things back in, it means that you are not eliminating stuff aggressively enough.
Smarter Everyday did a tour of the ULA facilities [0], which is also worth checking out if you like this kind of thing.
[0]: https://www.youtube.com/watch?v=o0fG_lnVhHw
