My dutch ovens are all cast iron, I haven't seen a porcelain coated one before.

Iron cook ware has plenty of thermal mass, so it stores a lot of heat. For burning the gravy flour, you probably should have let the skillet cool a while more, to do that, take the skillet off the heat entirely. If you leave the skillet on the electric burner, and just turn the heat down, it will take a very long time to cool skillet enough to add the flour. It's thermal mass hinders cast irons cooling on an on burner. Cast iron takes a little while to get used too, but once you learn it, you will never understand how you put up with the non stick stuff so long. It's all about remembering and managing the stored heat, once the skillet gets warm.

When I was 18, I won a set of nonstick cookware from a promotion at my then job. I used it for a couple of years, then decided I didn't like it, and started changing over to cast iron. I've been using cast iron cookware primarily for 20 years or so.