Don’t know to much about this but when I was looking at reducing temperature in the engine bay wrapping was an option and ceramic coating was another , + and - corrosion with wrapping, cost with coating but looks good .
I picked up a second hand sport manifold for my black top zetec 1.8L and has it Zircoteced (ceramic coating) and very pleased with the result. Looks good and works well. But as you say not cheap.
