“dossier author Christopher Steele.”
I take it that rumor about 4chan having had a part in fabricating the dossier was debunked?
No, not debunked, but not yet proven, either. The story is that Steele pulled some phony Trump FanFic off the internet to use in his "dossier" (also fictional). There was someone on 4chan that was claiming that the Trump story was his/her creation, but I don't believe that was ever proven or disproven.