After a good bit more reading, I've given up on Hamlet's Mill, and not lightly. I usually view it as a kind of shame to stop reading a book before finishing, but I frankly don't feel like it's worth it at this point. The book is far too circumambulative to actually communicate its deeper point, but I get the feeling that it's that way out of a desire on the authors' part to avoid criticism with lack of clarity.
From what I can gather (after reading several hundred pages of deep, dank, quasi-poetic prose), it's a general argument that many classic mythological stories (those stories in different cultures that Hamlet is based on) are a kind of folkloric embedding of knowledge of axial procession (the fact that the earth's axis wobbles every several tens of thousands of years). This point is only alluded to or barely said, and only very circumstantial arguments are made for it, at the request of readers to squint their eyes to blurry the argument to make it sound more convincing than it really is.
Instead, I've started reading Julian Jaynes' The Origin of Consciousness in the Breakdown of the Bicameral Mind for the third time. It's one of my favorite reads, no so much because I find it so convincing, but because it's that pleasurable mix of ancient aliens-tier imagination and speculation with at least passable science, neurology, linguistics and other research. This was an enjoyment I hoped to replicate in reading Hamlet's Mill actually.
I've been hinted that I might start doing book reviews at the request of many subscribers, and I might pick Bicameral Mind to be the first candidate after I finish it again. I put up a poll of commonly requested books on the forum, and Taleb's Antifragile, Herrnstein and Murray Bell Curve and an unspecified book by Nietzsche got the most votes, but I'll probably end up doing everything on the poll anyway.