I... dunno if these are suppose to spawn in other dimensions but it was kind odd seeing these appear while visiting the Aether... or maybe the Aether civilization had access to this ancient technology.

A whitelist is perhaps easier to work with since you can just add in a dimension number to have these spawn. Add in 0, they spawn in the overworld, add in -1 they spawn in the Nether, etc.

Using 'tetra-1.12.2-0.25.2'.