Thanks, MikeTO, for teasing out the issues.
I've written over 20 books using the non-WYSIWYG story editor in InDesign. I receive draft layouts from the publisher, then flow text into stand firsts, body, box-outs and captions. The biggest advantage is that story editor copy is displayed big and easy to read whether it's editing the 17pt stand-first or 8pt caption in itals. With eyesight not being what it used to be, that's a huge convenience. And of course, to counter one of the above comments, it's perfectly easy to write to length because text over-flow is shown.
So, what I'd like is a non-WYSIWYG non-format story editor for a text thread in Affinity. I'd like the font used in the story editor to be selectable and sized, and to be independent of what is used in the text thread. No need for text formatting. The only formatting needed is a first-line indent or extra half line space to separate paragraphs.
Thanks, anyway for a super application. I'm so happy I can leave the Adobe quagmire.
Tom Ang