According to my experience, the study of game-playing programs has two independent components: fairness/bargaining and enforcement. If you have a good method of enforcement (quining, löbbing, Wei Dai's joint construction), you can implement almost any concept of fairness. Even though Freaky Fairness relied on quining, I feel you can port it to löbbing easily enough. But fairness in games with non-transferable utility is so difficult that it should really be studied separately, without thinking of a specific enforcement mechanism.