I’m surprised there was no mention of operational CRDT’s, or CRDT’s generally.

Yeah, I glossed over a bunch of the things we tried near the bottom of the "In-Memory Database" section. One of the things was CRDTs.

We did a few days of CRDT investigation along with the other techniques and decided the juice wasn't worth the squeeze when we found a simpler solution to our problem.

That being said, we've actually retained a CRDT-like implementation in our codebase and have been considering moving shapes (which have a slightly different set of tradeoffs) to that model.

There's no need for CRDTs here because there is always a central authority.