Please take everything I say with 2 Tablespoons of salt, I’m no expert
I wanted to get this article out there, not affiliated but I found it very informational. It is a comprehensive look at seasoning cast iron cookware:
I had read from numerous sources that seasoning with flaxseed oil (I was going to us walnut cuz it’s similar and waaay cheaper) has been all the rage for a while now due to America’s Test Kitchen promoting it’s slippery polymerization. However there seems to be something not considered: durability.
Carbon content of the oil plays a role, see link. Apparently flaxseed just can’t render a finish as tough as Crisco or traditional oils like tallow/lard/bacon grease. You might apply several layers of flaxseed oil that will still serve you well, but it still won’t be as tough.
My idea: Mix oils! Is that a no-no? Why not use something like… 5 parts Crisco, 1 part flax/walnut? Then you get a little added slickness.
Anyways, let me know if you have any ideas on mixing oils. I will be reading this looong Chowhound thread some day that discusses all this at length: https://www.chowhound.com/post/ultimate-season-cast-iron-cooks-illustrated-757023?page=2