Everything Kim has decided that still needs an action on this side.
A social post, a blog post, a newsletter. Kim sees it on her link the moment you send it and can approve it, ask for changes, or turn it down.
Paste the manuscript text. Notes on paragraphs you didn't change stay exactly where they are; notes on rewritten paragraphs are kept and flagged rather than lost.
Each link is its own invitation. People type their name once and everything they leave is signed — no account, no password. Close a link and it stops working immediately. A link only opens what you scope it to: a beta reader on the book never sees the posts queue.