Zack Weinersmith has Ashkenazi ancestry, wrote a book with GMU economist Bryan Caplan, and seems sad all the time, which look like LW-friendly demographics, but I don't believe he would be kind to their nonsense! I can see him knowing the online side of the movement and not recognizing that the physical community in California is the really dangerous part.
I honestly can't bring myself to care whether The Last Psychiatrist is a Rationalist, Post-Rationalist, or just Basilisk-curious. I could read real books, on paper, by actual experts, with fact-checking instead.