It's funny: while I knew the new Open Book with ESP32 was working — it booted up as far as the boot screen, and our Focus UI framework was working well though to throw an error message about the SD card — I had not actually gotten the Libros firmware fully functioning on the new prototype. To be clear, I knew what needed doing — the TODO list was short, just two items long — but up until this morning, I hadn't made time to do them, and the prototype only made it this far:
Yes, if you look closely, there IS a MicroSD card in the card slot at the right; I just hadn't written the code to, y'know, deal with it yet. I also hadn't yet dealt with the bigger issue: getting the reams of language data to work not from an external SPI flash chip, but from the ESP32-S3's own Flash memory, in a dedicated partition set aside for global language support.
TL;DR: I checked off both items on the TODO list this afternoon, and now the Open Book with ESP32-S3 is a fully functioning prototype, with all the same functionality of the Abridged Edition crammed into a svelte profile with