“The seasoning on cast iron is formed by fat polymerization, fat polymerization is maximized with a drying oil, and flaxseed oil is the only drying oil that’s edible.”
Dozens of web pages on seasoning cast iron, and no two agree. This one went and read the chemistry. Seasoning is polymerized fat, and a drying oil builds the hardest layer. Folklore had the right pan and the wrong oil.