SneerClub

I think the overlap between LW and incels comes more from the pickupartist shit which was popular there for a while. And the incels (ignoring the woman who started the movement and her intentions for it) take a lot of their ideas from the blackpill 'I tried pua but failed and I have decided it is the fault of the world' thinking. So there is overlap but not directly, more of a common ancestor.

Absolutely, you can't keep pandering to the so called anti-woke and not end up with a lot of incel-adjacent people in your spaces, and the eugenics undercurrent feeds directly into manosphere perceptions about optimizing dating and tying your self worth to your splachnocranium/neurocranium ratio.

More specifically Scott Alexander has pandered pretty aggressively to the Dogged Good Guy demographic, and is also on the hook for being all about the 'merits' of neoreaction, and people like Moldbug and Emil Kirkegaard are semi-regulars in his comment sections.

Also worth noting that before the infamous EY editorial in TIME that called for airstrikes against foreign datacenters to prevent clippy from going rogue, the previous time they covered ea/rat was to report that they appear to have a serious sexual exploitation problem.

On a more speculative note, some staples of the movement like effective polyamory may have come about directly from early rationalist inability to get any on the regular. Apparently if you go reddit spelunking it appears they also went through a phase of trying to ~~brainwash each other~~ optimize into bisexuality to stave off sexual frustration.