Originally posted by put dispenser here:

Personally, I think its cheesing but I do it anyway.

There are many who consider other maps they transfer to as "portals".

There are also mods that allow metal portaling.

Devs when they originally were making decisions on such things, the head of the game wanted there to be no portals. Others wanted portals for everything. The compromised settled on was what you see now so even on the dev team there is not a full consensus really.

Thus do as you wish and play the game as you wish, devs did let you play the game in that manner (else you'd not be able to switch around with inventories) so consider that as well.