Whereas it is nice to have an extra slot to store one of these, they have been seriously reduced in usefulness by being made Daily 1 items. I would switch between my Elite Spider Cult Mask and Glowing Circlet as the situation warranted it - now I can only use each one once between rests.
As both of these items have been obtained using real money, I think this change is wrong - you've effectively taken away functionality I have paid for.
Also, the implementation isn't all that slick - I'd expect the one I place in the cosmetic slot to always show on my character, and when I activate others from my inventory/hotbar, their bonus would apply, but the appearance wouldn't now change. Instead, the first click now changes appearance by swapping into the cosmetic slot and the second click activates it.