Meshes imported with the beta mesh importer do not work properly with this tool, which is a bummer because I’m trying to use a model that has a poly count slightly higher than the 10k limit on the default Avatar Importer. This is with the LCL_Jacket_PufferCoat_001.fbx from the Layered Clothing examples.
With the beta unified Mesh Importer
With the default Avatar Importer