Off-topic:

Your book looks lovely, very much in the style of practicaltypography.com. Perhaps I'll follow along, despite being, as you put it, a "cryptocurrency skeptic".

I'm not sure if fixing this would look better than leaving it as it is (I'm not a typographer), but the "jumping" of the main body during the transitions to (and from) the rare pages that don't have side-notes, feels slightly jarring.