Yeah, that's the one thing I've always agreed doesn't make sense at all. Other magical items shouldn't be able to portal (maybe boss trophies or magic weapons, etc) as that would make more sense, but metal ores should be simply by virtue of the fact that you're literally wearing the stuff in refined form anyway. It's the one thing I've always switched off in QoL mods. Glad they're putting in the option to turn this off soon.