It'd be nice if fedpkg would clone anonymously all the time and then set remote.origin.pushurl to the ssh protocol. Fetching is faster over git:// anyways (since there's no auth or encryption).
That's not for fedpkg, but rpkg. So I will open the ticket there and close this one. I also have a set of patch to implement the idea.
See https://fedorahosted.org/rpkg/ticket/23