This is an obvious new function:
Mudbox need the capable to export to other 3D file format,(and in fact, be able to import more file formats too):
Like STL,(very important for 3D sculptors), WRML, and X3D. Other usefull formats could be the legacy .3DS, and some others.
Greetings:
Sergio Mengual
3D Artist-3D Generalist-3D Character Artist
https://www.artstation.com/artist/sergiomengual
https://www.facebook.com/Sergio3D2D/
https://www.youtube.com/user/sergiomengual