I think the skeleton json itself is always exported with a skin called "default".
It's why you can't make a new skin in the editor named "default". The default skin also doesn't show up under the Tree.
It has some limitations vs. skins that you actually create in the editor.
I assume you want to create the kind of skin that appears in the editor tree.
And then be able to tell the runtime to use that by default instead of the skin named "default" when the skeleton loads?
So, I guess.....
....
wait...
what?
