i also disagree that all infps are aloof. i think the aloofness has much to do with an inferior so instinct (subtype). and especially sp, which is by nature distance, hard to reach, in its own world, etc. a 4w3 infp so/sx looks way way different. or an so/sx infp 9w1.
i see e4 as focused on originality. which is a more specific distinction than authenticity. i see our concept of authenticity as mostly being relevant for Fi. Fi produces its own form of reason, and infps trust that reason bc its their most conscious, complex form of experience. authenticity and "true to yourself" definitely has more of a connotation that speaks to trusting one's own experience more than knowledge derived from communication and language experiences/symbols/shared concepts. i think both infjs and infps as 4w5s want to represent the world uniquely, but their firm hold on their first dom cog process and their eventual expansion to incorporate other balancing facets move them away from so completely identifying with their Ni representation or their Fi truths. i'm not sure if the need for individuality you mention, well, if when you say that you mean originality (e4) or authenticity (Fi). infp 9s seem to be very very serious about promoting individual freedom in the sense that one deserves to be able to reason out their own form of truth apart from the collective. this could be a kind of individuality, freedom for individual belief, but they don't seem as intensively absorbed in comparing themselves to others and identifying with all of the differences they find, oscillating between being extremely understanding and extremely critical, trying to find what is ultimately right and wrong at an individual level (the good-evil dualism).