I always thought it would be nice to see some kind of "maintainer profile" for each project, that the maintainers could set up: Is the project open to PRs? What is the quality bar for PRs? How much developer testing is expected before a PR is accepted? Are there any automated test coverage requirements/expectations? Sort of like a more structured version of CONTRIBUTING.md.

Also, statistics about past PRs: How long does it take, on average, before the maintainer responds to a PR, before it gets merged? What % are rejected or closed? How many edits do PRs for this project on average need before being accepted? What is the current incoming rate for PRs and what is the current merge rate? I could look at these and figure out if a project can sustain yet another incoming PR or if they are in over their heads. And it would help me understand what level of "done" they are expecting. Maybe some of these are even already available--i haven't really explored GitHub that much. Hope this helps.