Thanks! On the source: I honestly never planned this as an open-source project — the prompts plus the programmatic validation between stages are most of the product. But I'm planning a technical post soon that goes deeper into the architectural details I've been converging on over the past six months.
On scaling: context almost completely stops growing after chapter ~70 in the case of the Oz series. By my estimates it's chapter ~90 at the latest depending on the story — for practically any story, context growth flattens out around there. The theoretical limit of the system should be somewhere around 80 million words.