Just another crazy idea. To add item that redirect inventory stuff in shulker boxes you carry. It needs at least two lists i guess: for allowed items and allowed shulker boxes. For example we set a standart shulker box and some items on KotR and KotR just redirect selected items in all standart ones successively (when one is full it use next, like it works with bow and different type arrows priority). But if we rename one of that boxes with anvil KotR will not use it until we set it separately. It will be able to use 3 modes of redirection like KotO and will be crafted from KotO and some other stuff: like compas, shulker shell and anything else.

And KotO needs higher priority than KotR of course.

The core idea is reasonable, but I certainly doubt the implementation as you outlined it. Wouldn't it be better and less excessively sophisticated design to just implement new variation of shulker boxes that would automatically contain picked items according to white/blacklist attached to them, whenever they are in player's inventory? These aren't gonna have any problems sorting themselves out, since .onTick() event for items is fired from left to right and from top to bottom, cycling through all items in the inventory, with hotbar being considered top-most inventory row. That basically means that items that are "higher" in the inventory get to trigger their effects earlier, so priority of stuff being redirected to boxes or consumed by something like KotO fully depends on where items that cause those effects reside in the inventory.

Hm.. yes. Idea with new type of shulker boxes sounds better. I just didn't think outside the BOX here... haa!
Anyway, should I rename the title?

Anyway, should I rename the title?

Bother not, done it myself.

Maybe it could be that you add an "Orb of Oblivion"/"Dislocation Ring" to the shulker though a smithing table, or having an orb of oblivion inside a shulker will enable this behavior, I know the Orb is supposed to be a auto trash can, so maybe through some process it could be transformed maybe? Making it absorb a Forbidden Fruit will cease it's endless hunger or something like that... idk...