Given what Leonel knew about his Unnamed Lineage Factor, he also knew that his Metal Body would no longer be the exact same, and neither would his Divine Armors, for that matter.
He had an idea of where he would take his Divine Armor, but he still needed some time to refine it. He also wasn't sure if he had the skill necessary to execute it just yet either, but that wouldn't stop him from implementing his plan for his Metal Body either.
Ultimately, it was wrong to still call it his Metal Body. Leonel felt that a more accurate representation of what it was would be a Vital Body, or maybe a Nature's Body? Regardless, he definitely wasn't limited to just Ores, and it also wasn't just flames either.
If he wanted, he could be a lot like the Florer family and absorb high level Force Herbs, or ancient trees, anything of the sort.