I have only seen a few examples here and there but when looking at a story map, I have occasionally seen chapters that were marked locked. Does that mean no new chapters can be added to that chapter? Part of why I'm wondering is because one of the stories I'm writing is one in which there are a few chapters that I want to prevent anyone from adding branches to.
No. You can still add chapters to those chapters. As the chapter texts of the chapters show, they are in moderation.
