Modular chunks made it easy to drop between meetings without losing context. The Instrument Index section on tag numbering rules, especially the Excel import example where a bad spec map broke loop associations, stuck with me; that mirrors issues I've seen in oilgas prod. Some gaps: wished there was more on SPI admin at scale—multi-user locking, rule promotion, and CI-style checks; it's touched but thin, and I wasn't sold on the certification framing. Still, I don't second-guess arch calls around catalogs, area/unit hierarchy, and data ownership now.