Since I use blend shapes to deform my clothing the only solution that works well is vertex parenting the buttons to vertices on the clothes. It works fine in Blender, but UE4 does not import the button geometry because it’s not parented to the armature. I can bake the transforms of the buttons and then parent the buttons to the armature. I tried all sorts of similar procedures but without any success in importing these buttons and their transforms into UE4, either with or separately from the main skeletal mesh.
Something as simple and ubiquitous as adding clothing to characters should be supported in my view. What is the accepted standard for doing something like this?