I believe a better solution would to use a github clone such as gitlab, which sits on top of the git repo, and allows for custom code around the BIP process. Potentially one could even build Bitcoin into such a BIP system. If somebody wants to support a BIP he donates Bitcoins to that proposal. Somebody who actually implements the BIP can receive some percent of the bounty, while some percentage goes to the Bitcoin foundation. Via such a platform one could create assurance contracts to kickstart BIP developments or Bitcoin extensions (public infrastructure which is not part of the core, such as opensourced exchanges).