If you've not read Into the Woods by John Yorke, I'd suggest it highly for this type of enterprise.

https://www.amazon.com/Into-Woods-Five-Act-Journey-Story/dp/...

It's more for screenwriters, but his theses on plot, pacing, characters, and world are good and easy to read. It's a very good book.

The ideas for the pivot are great. Read the book, it's seriously good.