Joinmarket does sybil resistance via fidelity bonds, that is, you only coinjoin with people who first prove they locked up a bunch of bitcoin in a timelocked address. Sybils would have to spend a lot of money to do that, thus bankrupting themselves, so you're only left with honest people. I think emessbee can do the same thing, so yay. As for zerolink, its purpose is to prevent linking the equal amount outputs to their inputs and to prevent linking people's ip addresses to their inputs. I think I've managed to do the first part in a different way, so I don't think following the zerolink protocol would improve anything on that front. The other part seems achievable by just writing a client that runs over tor and creates a new identity for all three rounds. Thoughts?