Like everyone else in this industry, I've been aware of the leaked Google API documentation since it showed up in May. Thousands of proto definitions from the Content Warehouse. Rand Fishkin and Mike King have done good work analyzing the organic ranking signals.
I do local SEO for a living. Have for about six years. And the thing that struck me looking at the early coverage is that almost nobody was talking about the local-specific parts of the leak. There are entire modules in there - proto message definitions, scoring structures, enum types - that seem to relate specifically to local search and Google Business Profile evaluation.
So I've been spending evenings going through them. It's slow. The proto files aren't organized in a way that makes it easy to follow, and there's no documentation telling you what any of it actually does. You're basically reading struct definitions and trying to infer the purpose from field names and types.
I'm not going to publish anything speculative. When I find something where the field names are clear enough that the purpose seems obvious, or where I can cross-reference it with known Google behavior, I'll write it up here.
A few things I've noticed so far without getting into specifics. Some proto messages reference review signals in ways that go beyond the public documentation. I've also seen structures tying geographic coordinates to click metrics, and what looks like an entity resolution module that evaluates how consistent a business's information is across sources.
I don't want to overstate any of this before I've spent more time with it. But there's enough in here that I think it's worth documenting as I go. If nothing else, it'll be useful to have the analysis written down somewhere.
More to come.