>- The PR has surprisingly little meat. It contains 128k lines, but most of them are AI-generated documentation (86K lines, 68%). It also contains 9K lines of AI-generated tests (7%). So the actual code is just 32K lines (25%).

When you hear about a huge PR or change this should be your default assumption regardless of whether AI or otherwise.

Most huge PRs are only a few thousand lines of "serious logic" code. That code then spawns a bunch of duplication of logic, stuff like adding a dozen few thousand line handling routines to convert a dozen inputs into some single thing. Those then spawn several times their own line count in docs and tests and whatnot.