We have been tossing around some ideas to make Collection Stash more robust and easier to use with regards to adding new collectibles.
Instead of having mass-produced, original, and custom collectibles as three distinct types we would merge this into two types. Mass-produced collectibles anyone can add to their stash and collectibles only the creator can add to their stash (this would merge the original and custom types we have now). We would continue to submit anything that is mass-produced or a collectible type we currently support (statues, action figures, etc) normally. However, say you wanted to stash t-shirts but we don't yet support that collectible type. You would then add that as a personal collectible in your stash without a collectible type (this wouldn't be required anymore). Then say in the future this we started to support t-shirts, we would have a new feature that would let you automatically convert that into a mass-produced collectible that anyone could add.
This would allow us to support virtually any collectible type and let the user add anything they collect to their stash.
Let me know what you think of this idea.