I know this as been suggested before, but here it is again.
For a start, it is so frickin laggy in spawn. I know that terrarium is in spawn so new players can find it and all that, but a new world for it would just make it a much better experience for everyone.
Also, apparently @@Fuzzlr found a problem where if you shift click gold to some villager it eats it, or something like that. So he just turned off shift clicking in inventories for the whole of spawn. For people who pvp, they'll know how annoying it is to A: fill up your hotbar and B:Quickly fill your inven if you wanna surprise attack.
Maybe we could even get a new terrarium map (The one that was under the spawn before the last one) Plllleeeeeeeeeeeaaaaaassseeeeee
So creating a new world for terrarium would fix 3 problems in 1. Please consider :)