It's not /precisely/ what you asked for, but an active and well-organized contrib-style github-based repo can be found at https://github.com/6c37/crux-ports - this only really benefits contributors who have new ports to add or wish to maintain the ones already present in that repo, and therefore is not a complete solution. You'll still need to use the Flyspray bugtracker to request version bumps for core/opt/contrib ports. I'm just plugging it here in case there are some people that don't already know about it.

Also worth mentioning with regards to this topic is the git ports driver, which in my experience works better/faster than the httpup and rsync drivers. See https://github.com/6c37/crux-ports/wiki/Installing-the-git-driver-and-adding-the-6c37-repo for details.

Ryan