Cannot change box around tacet text (or any text)

I would like to adjust the looks of the “Tacet” text which appears below a flow title when the instrument is not assigned to a flow, but that flow being assigned to the layout.
In the layout options I can change what text is being displayed and the padding above and below it.
The font setting itself is located in the paragraph styles, there is a style for “tacet” and I can change font size, alignment and so on, which works fine, BUT…

what I actually want to change is the box around the word, and whatever I do to the values regarding the text enclosure (box? frame? “Rahmen” in German) no change is applied.
I tried this on the paragraph style for the flow titles: same here. Changing the font size is visible after closing the paragraph styles window, changes to the box (like ticking the box for showing an enclosure at all) has no effect.

Is this a bug?

I believe the settings you’re looking for are on the Tacets page of Engraving Options.

Ok, there I can at least specify if the border is shown.

I’m not satisfied with the box around the Petaluma font, there seems to be a problem with font metrics. With Academico it looks exactly as you would imagine, but using Petaluma Script the top line of the box is way to close to the text while the bottom line is to far away. It seems the font baseline or whatever the box uses as a reference is broken?

I therefore wanted to set the enclosure sides individually, which seems to be an option within the paragraph settings, but either the engraving options for the box do override these settings, or - as my experiment with the flow title paragraph style might suggest - these settings do not matter at all.

I solved my problem by using the Pori Rehearsal Enclosed font, but I’d still be interested if this is a problem specific to those two situations I examined, or if the paragraph style dialog is broken.

At the moment, you can’t set the padding for each side of the rectangle via Engraving Options, as you’ve found, but in the next major version of Dorico you will find that the options in the Paragraph Styles dialog will be respected for the Tacet paragraph style, and the Tacets page of Engraving Options will be removed.