As we work out exactly how the UI will respond when users move between editing content and template, we must be mindful of the fact that template parts are also independent entities in their own right.

While editing a post with the full template visible (#27847), it may be that users do not need to fully engage template editing mode to modify the contents of a template part.

We should therefore explore consistent pathways and experiences for template part editing, that are agnostic of the aforementioned contexts.