IMO the whole point of steel is to have a reactive plate so you can see a reaction to verify an impact at longer range than is possible to see bullet holes in a target. If someone shot my steel with green tip I would be pissed. If you shoot normal lead core rounds AR500 will hold up very well as long as you shoot 100 yards +. I have over 1000 rounds on a 1/2" target with zero pitting. The only place it deforms is when you get an impact on the very edge of the plate.
AR stands for abrasion resistant. The surface hardining is affected by heat and thus water jet cutting is the prefered form of cutting to not undermine the surface treatment.
I'm shooting a match June 2-3 and the owner of http://www.outbackweldingtargets.com/ will be ther and is bringing me a KYL setup. If there is anything you would like from him pay him, let him know to bring it to the match, and I can bring it back with me. You'll just have to come to New Iberia to pick it up.