I would love to have third sync options. Ulysses and Scrivener are fine. But it would be great to be able to sync with just .md files within folder structure, representing chapters and parts.
Metadata (notes, summaries, characters) would go in the yaml frontmatter: that section in the beginning of the .md file, separated by
--- three dashes from the text content.
Such files might then be editable with any markdown editor. Obsidian, Typora or whatever. And you might make the .md file openable with a click in the Aeon Timeline. It is just as opening an .md file in the system preferred app.