DRKV
Wall of Flesh
My only gripe is you can't really use them until you've already mostly beaten the game because they require ectoplasm. The wireless mod lets you get them as soon as you get the steampunker, which makes sense because that's when teleporters unlock.
I think the steampunker should just sell these items, or make the recipe something you can achieve with 1 mechanical boss down (teleporter + souls of night and light?)
The reason I made the teleporters only available in mid-hardmode, is because they are just a bit convenient. You can carry one in your piggy bank and plop it down wherever. If you die, it doesn't matter, just teleport back.
However, I do get, that some people might still want access to wireless tech earlier...
So, maybe I could add a config file, or something, so you can change the recipe?