This can be addressed if any tiddler of type text/vnd.tiddlywiki is processed by the section editor.
I think with TW 5.3.1 this can be done in a simpler way. One reason to use se-type field is to selectively activate section editor and also to process patch tiddlers.
I’d prefer using fields inside the tiddler, so each tiddler is self-contained, having both text and all its folding state.
I’m not sure why I have this preference, maybe because it’s easier to find and modify states (by hand)?
I agree with you in some, well many cases, but there are some cases it makes sense, you can also use ways to access the state tiddlers from the info panel, eg you could put a setting that show and change the visibility of buttons in a tab behind info. This makes the details easier to find.