15-chapters carries what only a stylesheet holds: numbering on the heading styles and two heading styles of the document's own. The round-trip legs now carry that stylesheet too — a style the file names but the built-ins never heard of can only be written from there — and one absolute assertion says the chapters read as headings, which a round trip cannot: both its sides go through the same importer, so a consistent misreading compares equal. A numbered heading style rides the package's factory slot; a second definition under the same id leaves two, and LibreOffice reads the first.
8.8 KiB
8.8 KiB