i thought it went in your mount slotUnless I'm wrong, the necklace works when it's in your inventory. You don't have to equip it. Maybe we could change the text from "wearer can transform" to "holder can transform"?
This one. This is the good answer. This is what in looking for in answers.I recall the mount hotkey has improved so it also works in your inventory if no mount is equipped.
I don't really think it's an issue to change the tooltip for, since it's an active item and not a passive.
If you "use" it, then you'll "wear" it.