Tuplet symbols don't use Musical Text Font, but FreeSerif
When selecting Bravura to be used as the font for the tuplet numbers, MuseScore doesn't use the symbols provided by the font. I've attached a screenshot showcasing the tuplet symbol manually dragged from the master palette (below), vs. what I actually get (above).
OS: Windows 10 x64
MuseScore versions tested: 3.0.0, revision: ef48b60, 2.3.2, revision: 4592407