I'm still working on a longer post of "what I got wrong, what I got right" (I have the basic text written out, but formatting for forums is tedious), but for now I have a very minor comment about an aspect that is kind of living rent-free in my head.
Zone 5 setting spoilers:
I found it unusually amusing that the Amaurotine Ancient society had tried so hard to make everyone uniform and nondescript out of some sense of communal abolishment of status and class, and yet going around Elpis, we see the immediate problem that nobody can tell each other apart other than using unique identifiers. In this case, hairstyle.
Some few NPCs have the talent for seeing aether, but not everyone can, and so hairstyle is the best they can do.