Solved! Go to Solution.
I think it will be. It seems to me that "collectables" are remembered by the whole game, not individual saves. Loading your old save won't give you that artefact, but for the purposes of getting the Tag for finding them all, that shouldn't matter if it's on the main menu list.
As I said, I can't confirm as I've still got artefacts to find myself, but I DID complete my comic, shiv door and training manual Tags/Achievements that way (playing just part of a chapter).