The idea of transcluding entire pages into another page has been more well-established in designs of, for example, #Logseq. So that works. You want to write a long-form page deeper into an outliner thread? You can use a backslash-dialogue to create that new page and transclude/link it in place. Works just as well. A few complex scenarios where you mix long-form text and outliner thought annotations don’t really work with this scenario, but that’s okay.