they can do some good “porting” with that stuff. it is considered porting because it removes material to make the ports and runners bigger. Its reallly effective with TPI runner tube setups. the material they use really opens up the holes in runner tubes and the TPI bases. and it does smooth it out nicely
It is also pretty good on other intakes as well.
Heads tho, i’m not sure how they do those, or if they can do those. they probly could but a port job via grinder is probly the better bet because you can control it better.