What is the hook to alter links in the Book Outline tree? What is the theme hook to alter links in the book outline like theme_menu_link__menu does for menus?  Or is there a way to make theme_menu_link__menu apply changes to a tree view of the Books?  Not the book navigation but the Outline.
Turns out there isn't one.  Had to go back to an ajax approach and update the book outline in the client browser.