The fine folks at Muse are working hard on the behind-the-scenes coding and such, which still leaves an opportunity for us lower-level opportunists to bring you nice widgets to fill in the front-of-house gaps... like this one!
Muse has basic underlining, especially typical for hyperlinks -- but we designers HATE stock underlining, don't we? After all, it was Robin Williams (our beloved writer and designer, not our beloved funny guy) who taught many of us to bold and italicize when Macs first started becoming mainstream. (Remember the term "Desktop Publishing?)
To that end, here is a widget to expand the options for underlining, should the need arise. And the need will arise, because proper underlining in design (using rules and strokes, and not cheesy text attributes) is not a bad thing at all.
This widget requires you to create a Character Style, name it, and then enter that name in the widget's flyout panel. Play with the other settings in the widget to style your underline, and then preview away. All text to which you have applied your named Character Style will publish with the underlining style you created in the widget.
Watch the tutorial