"Pack Rat" Mob and chest all overworld inventory expansion

Inventory is obviously a hot topic of minecraft. i am in the "no backpack" club. however a late game overworld mob, the pack rat, that would "organize" your inventory. Here is my plan;

Craft a cage with sticks, copper (needs more uses) 

Use the cage to keep/catch the pack rat in. must have the cage and the mob is incredibly rare in the over world. thus you have to keep the cage with you incase you find one. Or maybe a tamed cat has to catch it for you?

Then combine the cage with 8 chests to pack a auto organized chest, like the auto sorters we all build we can place one of the items we want into that chest and the pack rat keeps it organized. 

Would like to see this idea where its placed like a Ender chest and can be taken with but must be mined with silk touch axe. 

The idea would be that you could have it so all stone goes into the pack rat chest from your inventory automatically (or whatever items you choose) but the chest must be placed down to access. 

I feel this is a good way to expand inventory while not making shulker boxes useless, obtainable with out the end, but not super easy early game.