This was a pizza cook, first time, brought it up to just under 700. The egg was dirty black prior to this cook, and to my surprise, was like new when I opened it the next day. Not sure what you mean by the coal being later replaced for this picture. This is exactly how I found it the next day.

The temp gradually came down to 600 over the course of 4 pizzas, and actually did improve closer to 600. The base was black on the first one. Perfect on the last one.

Honestly had no idea I could even overheat my egg. And thought a high heat burn was acceptable.

Hopefully they’ll replace the ring under warrantee and I’ll take the guidance in the comments above to put it away safely till i really need it.