Today, I did some writing where I tried actually using the reference material I've been putting together for the past week or so. It worked fine, although I did have to errata some rules interactions I hadn't anticipated.
I also made some changes to Structured Data to hopefully make individual pieces of the code easier to understand. Honestly, I can't tell if it helped, but it occurs to me that I have seen some projects take the "define things internally and re-export" approach, so that's heartening. If I go all the way with that (which would really help some metrics), I'll probably have to ditch the whole "type facade" idea, or else go all in on that as well. I don't know which I really prefer. Either way, I'm probably going to have to keep up the "split of into modules" thing, and possibly start adding more folders.
I've got to wrap up.
Oh, also, my code is so horrifyingly un-idiomatic that I had to pin Mypy to an earlier version and file a bug, because the latest stable and dev both crash with AssertionError: unreachable which is clearly false.