Unable to export helmet rig skeletons

Its a “no-go” on helms so far for me.
Currently when importing the MaleBurlap_Hat_Skeleton.fbx into maya, the skin info is gone and the “joint2” bone is also gone. However when importing into 3dsmax I had to convert the dummy into a bone but even after I can’t export it back out into maya. The joint simply vanishes.

When importing the mesh with MY joint2 created within maya, it gives me errors asking me to recompress animations with the risk of invalidating them.
(Joint2 is used by the burlap hat… I have not seen any other hat/helm in the assets needing a skeletal rig. Can a dev point the way to understanding how and why the helmets are done this way? Also, sockets - do I need to create one for my own custom helm to even sit properly?)