Ok, now I realize that the focus bar is actually split into blocks
title / author / author affiliation
that reflect a hierarchy in the document, and each of the block can have its own wrench. That makes sense now, but I find it difficult to follow especially for beginners.

It took me some time to learn how to position the cursor in the document, such that the focus bar displays what I need (e.g. when I want to change the font size). I concluded that, as rule, the focus bar reflects the surrounding context only. Are titles an exception?

I think I was also confused by the fact that in the title block, the sub-blocks (author and author-affiliation) are never shown by a cyan box, so I never realized the existence of this hierarchy.

I am not sure how to fix this. Maybe replace the space between the title / author / author-affiliation blocks in the focus bar with something more explicit, such as ">>" ?

All this shows that it would be nice to have a more direct access to (the settings of) all the enclosing blocks for the current cursor position, in some kind of vertical navigation bar.