My eyes started to glaze over after a bit; so what I'm getting here is there a group that calls themselves "Rationalists," but in just about every externally meaningful sense, they're smelling like -- perhaps not a cult, but certainly a lot of weird insider/outsider talk that feels far from rational?
Capital r-Rationalism definitely bleeds into cult-like behaviour, even if they haven’t necessarily realised that they’re radicalising themselves.
They’ve already had a splinter rationalist group go full cult, right up to & including the consequent murders & shoot-out with the cops flameout: https://en.wikipedia.org/wiki/Zizians