Update: I found a way around the save problem! The new build now picks up your old save automatically, so nothing gets lost. Your suggestions are in: the Hollow now stops at the Rot's source, and the constellation ending is clearer. Full details here: https://zer0fast.itch.io/hollowrun/devlog/1668881/update-11-your-biome-is-saved-...
Thanks again, this update exists because of your feedback.