I’ve thought about this since launch actually. My ideal would be a single equip slot with a hide/show option like mask, shoulders, back. This would make it easy to carry around a favorite and also alleviate the problem of Deposit All Collectibles making them disappear.
I like minis, but I never have them on me, either due to inventory space or because I recently deposited them on accident. If there was an equip slot for them, I might actually be inclined to buy some.