Still, to the extent that they do converge on reliable truth finding mechanisms, they should converge on the same truth-finding mechanisms. And one's admission that one's own truth-finding mechanism is so heavily school-dependent would indeed be quite worrisome, as it indicates insufficient critical analysis of what one was taught.

Not sure how this engages with my challenge. The idea is that different schools might not all be converging on "reliable truth finding mechanisms". Maybe only one is, and the rest are like (non-obvious) cults, in respect of their (non-obvious) unreliability. [I'm not suggesting that this is actually the case, but just that it's a possibility that we need to consider, in order to tighten the arguments being presented here.] As the cult analogy shows, the contingency of our beliefs on our educational environment does not entail "insufficiently critical analysis of what one was taught". So I'm wanting you guys to fill in the missing premises.