As far as interpreting "steel" my experience with lds is that whatever they say at the moment is the interpretation.
Well, if they can find a little bit of “steel” from 4000 plus years ago, you would think that the vast amounts of “steel” left lying about after 100’s of thousands were killed in battle could be found.
And you bring up another good point. Since mormons used to claim, and some still do, that the ancients of meso-america are/were the peoples referenced in the BoM, why weren’t smelts and foundries discovered during the excavations of those areas?