The confusion arises partly because since Tinderbox v6.5.0, the ‘Text Pane Selector’ is hidden, by default, in new documents. There will be many tutorials, demos, etc, written before then which would be unaware that some users may need to un-hide the selector controls before they can be used. The toggle is document wide - turning it on anywhere turns it on for every note in the document. Furthermore, the show/hide state is remembered from session to session. so turn it on for the documents that need it, e.g. for export and leave on whilst for other documents the default layout may be more useful (more room in the text pane for other content). Or, you can toggle the controls on/off as needed.