[mp] Streamline interface for MP material laws
TwoPOfT came up during headercheck. Seems like it's unused. We could also remove it completely. @heck depends on if you are gonna have a usage for it in the future.
TwoPOfT came up during headercheck. Seems like it's unused. We could also remove it completely. @heck depends on if you are gonna have a usage for it in the future.