My point though is that heavier elements are not a by-product, but rather something that you need to deliberately manufacture, which means that you don't necessarily have an overabundance of them as it then becomes an issue of economics and supply and demand (even if they are easier to produce than by current standards), and this is the sort of thing Brandon is usually careful about having in-world explanations for (i.e., having the heavier elements as by-products essentially contradicts his third law of magic by introducing new magic physics unnecessarily, whereas adding a one-liner explanation for easily manufacturing it wouldn't).