I'm still coming to terms with the philosophical definitions of different positions and their implications, and the Stanford Encyclopedia of Philosophy seems like a more rounded account of the different view points than the meta-ethics sequences. I think I might be better off first spending my time continuing to read the SEP and trying to make my own decisions, and then reading the meta-ethics sequences with that understanding of the philosophical background.

By the way, I can see your point that objections to moral anti-realism in this community may be somewhat motivated by the possibility that friendly AI becomes unprovable. As I understand it, any action can be "rational" if the value/utility function is arbitrary.