My pedantic notes, modified by some of my experiences, so bla bla epistemic status, colored by my experiences and beliefs take with grain of salt etc. Please don't take this as a correction, but just some of my notes and small minor things. As a general 'trick more people into watching into the abyss' guide it is a good post, mine is more an addition I guess.

SSC / The Motte: Scott Alexander's devotees. once characterised by interest in mental health and a relatively benign, but medicalised, attitude to queer and especially trans people. The focus has since metastasised into pseudoscientific white supremacy and antifeminism.

This is a bit wrong tbh, SSC always was anti-feminist. Scotts old (now deleted) livejournal writings, where he talks about larger discussion/conversation tactics in a broad meta way, the meditations on superweapons, always had the object level idea of attacking feminism. For example, using the wayback machine, the sixth meditation (this is the one I have bookmarked). He himself always seems to have had a bit of a love/hate relationship with his writings on anti-feminism and the fame and popularity this brought him.

The grey tribe bit is missing that guy who called himself grey tribe in I think it was silicon valley who wanted to team up with the red tribe to get rid of all the progressives, might be important to note because it looks like they are centrist, but shock horror, they team up with the right to do far right stuff.

I think the extropianists might even have different factions, like the one around Natasha Vita-More/Max More. But that is a bit more LW adjacent, and it more predates LW than it being a spinoff faction. (The extropian mailinglist came first iirc). Singularitarians and extropianists might be a bit closer together, Kurzweil wrote the singularity is near after all, which is the book all these folks seem to get their AI doom ideas from after all. (if you ever see a line made up out of S-curves that is from that book. Kurzweil also is an exception to all these people as he actually has achievements, he build machines for the blind, image recognition things, etc etc, he isn't just a writer. Nick Bostrom is also missing it seems, he is one of those X-risk guys, also missing is Robin Hanson, who created the great filter idea, the prediction markets thing, and his overcoming bias is a huge influence on Rationalism, and could be considered a less focused on science fiction ideas part of Rationalism, but that was all a bit more 2013 (Check the 2013 map of the world of Dark Enlightenment on the Rationalwiki Neoreaction page).

"the Protestants to the rationalists' Catholicism" I lolled.

Note that a large part of sneerclubbers is (was) not ex rationalists, nor people who were initially interested in it, it actually started on reddit because badphil got too many rationalists suggestions that they created a spinoff. (At least so the story goes) so it was started by people who actually had some philosophy training. (That also makes us the most academic faction!)

Another minor thing in long list of minor things, might also be useful to mention that Rationalwiki has nothing to do with these people and is more aligned with the sneerclub side.

There are also so many Scotts. Anyway, this post grew a bit out of my control sorry for that, hope it doesn't come off to badly, and do note that my additions make a short post way longer so prob are not that useful. Don't think any of your post was misinformation btw (I do think that several of these factions wouldn't call themselves part of LW, and there is a bit of a question who influenced who (the More's seem to be outside of all this for example, and a lot of extropians predate it etc etc. But that kind of nitpicking is for people who want to write books on these people).

E: reading the thread, this is a good post and good to keep in mind btw. I would add not just what you mentioned but also mocking people for personal tragedy, as some people end/lose their lives due to rationalism, or have MH episodes, and we should be careful to treat those topics well. Which we mostly try to do I think.