Do you have any recommendations on introductions to alchemy? I had spent some months looking into it maybe five years ago but found it more-or-less utterly opaque.

There's really not a lot written about Teiresias; a few paragraphs scattered among several sources. My overview from a few weeks back is sadly pretty comprehensive, and the sources are cited; the main source which I explicitly avoided was Ovid, since I don't trust him for spiritual use (though the Metamorphoses is, of course, quite entertaining). I found Kallimakhos's hymn on the Bath of Pallas particularly moving.

Regarding "all models are wrong," you're welcome! I learned it when I was studying statistics in school, and it's stuck with me as a more useful version of "the map is not the territory." I think it deserves to be better known than it is (as I do with Bayesian statistics generally), as Western culture badly needs an antidote to it's dogmatic tendencies.