This seems revisionist to me. There was a whole thread dedicated to identifying every Belfast restaurant that serves Poutine because Keffals said something to that effect. People were talking about or implying bomb threats everywhere in that thread. I definitely saw it, but obviously I can't link it because CloudFlare.
It's just not true that KF engaged in serious moderation. If they had, they wouldn't be a community engaged in targetted harrassment, and they are very clearly a community engaged in targetted harrassment.
And to repeat: you seem really engaged in finding a way to make them not, or make their enemies just as bad. When... maybe you could just not defend them? If you want to make a 100% principled argument for Free Speech, go right ahead. But don't nod to the idea of moderation like you are here and then pretend that it works when it doesn't.