I wonder if they have any type of requirements for the home shop. I dont have a true belt grinder, but I have a makeshift one that works ok. I mostly forge a billet, and put it on my home made CNC. Id look at it as the same as stock removal with a grinder, if i just cut the outer shape with the CNC.
I also wondered how the steel and abrasives work. Do they give you steel to work with? What about problems at home, like your press brakes, or your sander brakes, do they pause the recording while you are down for maintenance? ALSO i thought about the tempering thing as well. I was convinced they didn't do it, but i always wondered how they don't break. Then I saw walter sorrels blade break, and it convinced me they don't temper the blades.