There is no reason for this limitation what-so-ever. My weapons and armor are made of the very same metal but somehow that can be teleported? It seems this is just some cheap way to extend the gameplay when really all it does is burns the game out faster. If the goal is to make the game "realistic" then take out portals all together.

The mass majority of game time is running a handful of metals back and forth every time my bags are full. If it weren't for fact that I could circumvent this by logging in/out of another world to drop off items and retrieving them at my main base I would have been done with this game after entering the iron age. I love this game but does anyone have a logical explanation to why the devs limit metals to being teleported?