Norma I personally like the look of your latest pies. It's in line with my favored or ideal type of crust/crumb. It's not for everyone though. So what I would consider "perfect" others who eat it may just say "meh, not my cup of tea". All I know is that it's a very specific type of crust and crumb and it has a very specific look to it. The crumb is not spongy like neopolitan pies. And when i get it right, it's pizza heaven. It's way better than my other mediocre pies using the SAME formulation. But zeroing in on the right hydration ratio for the right moistness, right oven spring, and right crumb texture balanced with the right baking temp and you have it. You can do it using the very formula you've been using for a year now. Get those essential elements to line up (with the moon and stars of course

) and the crust will take on an amazingly different quality. It's not easy though so I hope at least one person on this board can do what i have done to validate that I'm not losing my mind.
Your crumb shots look very airy and similar to mine despite using a different recipe which solidfies in my mind, it's not the recipe. It's the way the dough is handled/made and it's the way it's baked up. If you like an even loftier/airier crumb like my perfect pies, it's easy to do for you. You are 80-90% there. All you have to do is up your hydration ratio a bit. If you are using a Lehman dough and your hydration ratio is around 63-65%, then just up it towards 69% to see the difference. Bake it the same way in your grill and stretch it out thinner and you should be eating what I'm eating.
If your bottom is getting darker before the top, here's a trick I use. Just monitor the bottom and when it's brown (not charred), slip the pie on a comparable size FLAT (no rim) pizza pan. It will slow down the bottom cooking drastically and buy you more time for the top to catch up.
Would you mind doing an experiment for me? Next time you bake on the grill, up your hydration ratio by 5% (so say 63% to 68%) and stretch it thinner and see what kinda of pie you get. And don't worry about the spring of a thin dough. B/c your bake temp is right, you will still get HUGE spring.
Overfermentation: Unfortunately I'm no expert and can only share my experience. The doughs look very poofy. The only way I know how to gauge overproofed dough is when it rises to more than double and can't seem to support it's own weight. But that is way overproofed. I generally shoot for about a 75% increase. A little more is ok too. The 2nd indication (albeit less scientific than the first

) is that the pie seems to darken or burn prematurely or faster than expected at high temps. when my dough is properly fermented, it will take a 700F for 4 min and get a dark but not burnt bottom. I might even say 750F for 3 min is fair. If it darkens or burns prior to that I consider it at the beginning stages of over-fermentation. The more overfermented the sooner it will burn. As an extreme example, I posted (in my MBE thread) a overly fermented dough. It started to burn at below 650F in around a minute and a half. I ened up letting that one really burn to try and play around with darkening the rim a bit. I realize my undertanding and explanation may not represent truely what is going on. So experts feel free to correct me.
Again, very nice work.