What would have made sense, indeed, in regard of some other fantasy settings, is to make raw metal incompatible with the use of eitr and portals. Exception could be silver or exotic metals (like the werewolf/vampire/faery vulnerability). But forbidding most metal-made items would have been too much a constraint, and then players should rejoice to be able to bring with swords and armor, instead of comparing nails with ingots, imo.

However, now that we have those settings, perhaps there will be another one for portals: Allow all - Restrict ingots (as currently) - Restrict metal