I’m using one document to take notes, outlines, etc for my NaNoWriMo novel, and another document for writing the draft. It would cool to be able to specify, for example, a different font for the manuscript vs the notes document.
But I can see how that would complicate the Settings pane.
I expect themes will solve this and that’s what I plan to work on next. Keep an eye out for 1.18 preview versions in the coming weeks.