Technical reasons prevent SE from doing a glamour "closet" the way we'd like... but that doesn't mean an alternative couldn't be implemented within existing game code.
What if there was a Glamour Vendor that worked the same way the Calamity Vendor does. Any item appearance you have acquired gets unlocked on this vendor so you can use the appearance, get rid of the original item, and re-buy a binding (non-tradeable/non-sellable) version of it from the Glamour Vendor any time you need to re-glamour. In this way an existing mechanic is used (the calamity vendor code) and we aren't forced to tie up precious inventory space with our glamour gear.