Single use skins with transmutations
If you get a drop of a single use skin. It's obviously single use to apply it to an item. But can you then transmute that item skin to other items using a transmutation stone/crystal?
Sure can!
The skin of an item is independent from everything else. As long as you have a transmutation crystal (if the stats are level 80) or transmutation stone (for lower level items), you can pass the skin around from item to item ad infinitum.