I'm trying to have text such that
- One set of paragraphs appear in the center of the page; when there is no more room, the text flows onto the next page (see blue area).
- Left of that, text wrapped around the central text such that it flows from 1, to 2, to 3; then, on a new page, back to 1 again , and so forth (see red area).
- Right side, text wrapped around the central text such that it flows from A, to B, to C; then, on a new page, back to A again , and so forth (see green area).
Ideally, the different texts would flow continually page by page (in their red, green or blue areas).
I suspect the solution is flowfram, and I've tried in vain to use this excellent answer but I'm just not managing it...

flowframcould be the easier solution. Check if this example (with a different layout) help you to understand the syntax. The "but" is that you cannot have fully automatic text flows in blocks as 1, 2, 3 because the text width cannot be changed in the middle of a paragraph, so is your task ensure that every block have only complete paragraphs or place a\framebreakwhen needed. – Fran Jan 19 '21 at 09:13