I’ve been shooting them for more then a decade. I’ve bent two 500 spine out of my longbows.
I’ve never bent a .250 or .300 spine from my compounds and I shoot 80lbs at 30” DL. They’re tough.
I foot the front with carbon express nock collars the same as I foot my carbons.
I don’t think the reduced diameter makes an inch of difference for penetration but I don’t think it hurts either. Back in the day I never had penetration issues with my XX78’s in 2219 and they were much fatter then any common carbon or micro diameter shaft available today.