They rate it to +p which is arbitrary, but that’s not the point. It’s still a blowback 10mm. Even if it holds the pressure of the shot, the action on the gun is going to take a beating with each shot. The gun, if ran “hot” starts battering itself to bits as the springs weaken then your still going to see an action failure. Remember the quality of gun your looking at too. The majority of the gun is plastic with stamped steel bits in the right places. You probably will not be able to see damage like you would on a steel gun where discoloring and galling happen either, so it will be difficult to assess the “health” of the gun. It will go til it blows... be careful.
Not to sound negative towards the gun, I’m not. I do have interest in it and may very well buy one, but the materials used and the hi-point mechanism are not a good fit for a gun that powerful. It will have power or longevity, but not both. If I buy one it will get hand loaded ammo just strong enough to reliably cycle it. And the stamped steel dust cover will be off of it regularly to inspect it internally.