I have had several disasters in my P134H and the stone is fine. No traces of that anymore. As Scott said, the temperature is high enough that everything burn up. That includes dough, sauce, cheese, toppings etc.
What you should keep in mind is that if you lose something on the stone, it will produce a lot of smoke. If disastrer strike, my goal is to remove as much as I can from the oven with my metal peel, then close the door and let the rest burn to ashes.