Your understating things quite drastically.

If I spend real money for something, and then you want me to spend more money for space to store it, that just aint on... and don't you dare try to tell me this game don't try to charge you to store things.

If the Armoire is just a list that can only accept certain items, fine. It's a checklist, why not make the checklist much larger?

Why is the calamity scavenger and recompentence officer separate people? If they are checking a list of achievements to see if you have them, so they know what items they can let you have, why can't the Armoire do that too?

So, now you've got a big storage chest that holds the raw items only (before decoration or dye), for things purchased from the store, earned from achivements, or are rare and noteworthy enough that the game wants you to recover them latter once the plot has let you have them

Would this be a bad thing, or just impossible with the code as it is?