I write books in Vim. The way I work is that I do it all in plaintext until the final edit. Only after that do I add formatting (could be .docx or Markdown or whatever the editor expects).
What happens when your editor requests changes? How are those edits communicated to you, and how do you integrate them back into plaintext?
(Serious question—a big pain point for me is the choice between using my preferred tool to start, then switching to a bad tool later; or, using a bad tool the entire time)
All edits in plaintext on both sides until the final draft. Yes, I know this isn't the standard way of doing things but it isn't so much because I'm a Vim cultist or anything. It's only because I can yank, insert, and navigate the text so much faster than with something like Pages, MS Word, or Scrivener.
Another way that seems to work well for some writers and editors is a shared Google Doc.