I don't know if it's already been suggested, but here it is:

Artifact Bank - a base structure allowing players to deposit/withdraw artifacts (depending on permission level)

I hate selling artifacts, but because I am an active trader, I constantly need to make room in my cargo, even though my available space is considerable. An artifact bank would allow players another way to contribute to their legion without being forced to scrap artifacts. This could be extremely valuable for lower ranks who are not yet large enough to get mass storage pods from artifact shipments.

it has been suggested before ever since the legion system went out.

Ah, k. Did a search for 'artifact bank' and got nothing useful on the first page. ^^