i did for two years. i wrapped barrels, built and bedded stocks, and did muzzle crowning and threading. i am not a machinist or gunsmith but rabid enthusiast with a thirst for knowledge.
i try to avoid posting specific details that aren't intended to be public knowledge. what i was getting at is their contour lathes do not need special soft steel to do their job. it's barrel steel. it should last in the ballpark of other cut rifled barrels (a bit longer than button barrels). the carbon fiber has a low thermal mass and, depending on how you wrap it, will either be stiff but insulate or be less stiff but shed heat more quickly. proof's regular wrap pattern sheds heat. so they don't behave exactly like a normal steel lightweight barrel. the characteristics change a bit.
when i say "monster lathe," mind you, i'm not talking the beasts that turn three foot stock into bearings. i mean relative to normal shop lathes. they don't need to handle anything bigger than a barrel blank.
also, my interest in posts about proof barrels and processes is due to a general lack of understanding about them. they (proof) don't share a lot of information, and people ask a lot of questions and make a ton of assumptions, many of which are incorrect. my two cents are typically trying to clear up questions or misunderstandings. and if i can learn something at the same time, even better.