Someone may have mentioned it, and i just missed it, but i'd actually prefer what WoW is doing with theirs in Legion. It records everything you could have gotten from quests and gives you access to it, even before this feature was added. At least that's the promise. Keep in mind though, it took WoW over 10 years to get this in, after having transmog and void storage, which was only added after removing keys or some such that made room for the data of item looks.

I say this as someone who has two and a half retainers full of glamour gear.