Hey Militant Squatter...I tried every conceivable setup using the XL Egg ...especially a lot of different ways of heightening the surface into the dome ... nothing really worked... 2 things.
I discovered that raising it only works for , maybe , early in the baking as when you lift the lid the lid (dome) cools quickly ... anyway ..the height ...it didn't seem to work as I thought it would ...and the bottom still always would burn before the top was done ...this is over maybe 6 pies .. baking time period ... I also tried 13" , 14" , 15" , 16" and 21" stones ..and a special D shaped one that you can see if you look at the bread baking vids on my website...
I eventually gave up on the XL and went back to the large because fire is "deeper" ...further away from the stone after the coals burn down a little ..
I have a whole technique that is repeatable .. using the "traditional " setup ..which I eventually went back to ..after a year of trying other things ... platesetter legs down , feet, stone on top of them ... as of now, this setup still works the best for me but I do a LOT of preburn to charge heat into the dome..I have videos but haven't had a chance to edit them and post them but I will ...I seem to have a really good , repeatable system and the top gets done great ... but still, after an amount of time, the stone gets too hot and the dome loses "heat charge" from being opened ...but I can get 4 or 5 perfect pies .. one of these days I'll post it all .. let me know how your experiments work ... I burned a ton of crusts using the XL...hope you figure it out and let me know etc. .
PS ..I think the BGE pizza vids on the website are using my latest setup and system