Upload the manuscript of each edition, and the studio reads its structure: the title page, copyright page, dedication, parts, chapters and back matter. Every ebook and print file is then built from that one manuscript, so the paperback always says what the ebook says.
What you need: the edition's text as a Word document (.docx), an EPUB from any program, Markdown or plain text. From Google Docs, choose File, Download, Microsoft Word. From Scrivener, compile to Word: the Scrivener guide has the settings that bring your chapters and scene breaks through.
How chapters are found: in Word, give each chapter title the Heading 1 style (and each part, if the book has parts). Lines such as "Chapter 1" or "Prologue" are found even without the style. A line of asterisks marks a scene break, and so does an empty line between two paragraphs, unless the manuscript has an empty line after every paragraph.
Lists, quotations and sub-headings: bulleted and numbered lists (up to three levels, and a numbered list that goes on after a paragraph keeps counting), quotations set off from the text (in Word, the Quote or Block Text style) and headings below the chapter's (Heading 2 and 3 in Word, ## and ### in Markdown) come in as they are, and ebooks and print set them so. Tables come in as tables, their header rows and cells across columns kept (up to 12 columns: a wider one comes in as a paragraph a row), and ebooks and print set them, a little smaller than the text. Cells merged down a column keep their words in the top cell, and the cells under it come in empty. A table of one column comes in as its paragraphs. Boxes set off from the text (a sidebar, a tip, a game's message) come in as boxes: in Word, a text box, a paragraph with a border round it or a shading, or a table of a single framed cell; in an EPUB, an aside or a box the page draws; in Markdown, an alert such as `> [!NOTE]`. Ebooks and print set each in a thin frame. Verse keeps every line where you broke it: a stanza is a paragraph whose lines you broke with Shift+Enter in Word (or a Poem or Verse style), lines ending in two spaces in Markdown, a poem in an EPUB, or short-lined stanzas in a plain-text file. Ebooks and print set each line on its own, a line too long for the page going on indented under it, and keep a short stanza on one page.
Pictures: pictures in a Word document or an EPUB come in where they stand in the text, with their captions (in Word, the Caption style under the picture) and their descriptions (Word's alt text, which ebooks read aloud to readers who can't see them). A picture alone on an EPUB's page gets a page of its own in print; the EPUB's cover is left out, as covers are made in the cover editor. What a camera or program wrote about a picture (where and when it was taken, the camera, comments) stays out of the book. Ebooks carry a lighter copy of each; print uses the original at up to 300 pixels an inch, and the build says when one would print soft, or in grey on cream or white paper. Markdown can't carry its pictures: upload a Word document or an EPUB for those.
Notes: footnotes and endnotes come in from Word, from EPUBs made by other tools, and from Markdown (written [^1], with the note on a line of its own starting [^1]:). Print sets each note at the bottom of the page its mark is on; ebooks gather them on a Notes page at the back, each linked to its mark and back, which Kindle shows as a pop-up. Notes are numbered in the order the text first marks them; a note marked inside another note comes in as a note of its own, numbered right after the one that marks it. A mark on a heading moves to the paragraph after it, after its last word, as headings also go into the contents. In the manuscript editor a mark shows as its number: deleting it takes its note out when you save.
What you get: a short report of what the import found and what it changed or left out, the chapters and word count on the book page, and builds for every format. Upload a new version whenever the text changes; the next build uses it.