Why is this not a feature? Even simple barebones UV packing would be useful instead of having to manually drag everything around to export to a game engine.
For my use case, the UV's in marvelous designer are crucial because I do multiple different exports of the same outfit in different states. As such I need to do UV packing in marvelous designer so that each Export has the same UV's so they can use the same textures and materials.
When doing tons of outfits though having to slowly manually pack UV's really sucks, and is also much less efficient than an autopacking solution..