Agreed about the lack of monorepo tooling. There's just not that much out there. A couple of other links I didn't see in the awesome-monorepo:
- https://github.com/facebookexperimental/mononoke - I hear this is a real thing and not a science fair project
- https://github.com/bors-ng/bors-ng - Needed in a monorepo to handle high arrival rate of commits / merges