Personally, I think discussions should happen organically over any channel; a tool like Github only gives a false impression that everything happens there, but really it usually doesn’t. Regarding dashboard for maintainers, there are tools that do it well, but usually they are dedicated to that; I don’t think using PRs or issues gives a complete exhaustive picture of what needs to be done, and forcing every maintainer to use one lowest common denominator tool like Github is these days doesn’t seem like a good idea.

As far as checkout, doing it with an emailed patch is one command, actually.