I have emailed Marvelous Designer support about my issues with the FBX files. The animations were being lost in the import, MD they have replied to my request but I don't understand what they mean. Can someone explain to me what their feedback is?
"According to your concern, alembic export does not seem to have any problems. (Please find the 'Test_Alembic.Zprj' file.)
About the FBX file, we believe that the animation is omitted because you didn't bake the node key named "Amature". (Please find the 'Test_FBX.Zprj' file.)
Since this issue is related to Blender, we believe you will be able to get a better solution from Blender support team.
If you have any further questions regarding this issue, please forward the issue to the official support team in Blender.
Thank you.
All the best,
Marvelous Designer Team."