That’s one thing I always found strange about Layout in that there is no Entity Tray in Layout (another item Sketchup and Layout lack that consistency) where in that tray, it shows what is selected (and if multiples are selected, how many) on a page, be it a text string, viewport, dimension etc, you know, Layout Items (not so much Sketchup models/entities). In fact, that Entity Tray can eliminate the need for a separate Text Style tray, Dimension Style Tray and whatever else as those would all be dynamic attributes of the Entity selected and show up in the Entity Tray.