A section opening on a side hands its one-page master over to a follow-up
master instead of asking for a right-only page, which doubled the page count.
DOCX names its default style Normal and marks it as the default, zone tabs
stay tabs, footnote numbering rides in the section properties, and w:position
counts half-points. The importer keeps content controls, shape text boxes and
index page numbers, and opens no phantom section on the leading master.
Editing rejects the nesting the formats cannot hold, note repairs ride the
undo history, and the showcase files are rebuilt.