I'm liking that olive pie.
As for suggestions, IMO, something's not right with your temperature measurement. If you are not using an IR gun, you need to be. If you are using an IR gun, then check the calibration b/c I think it's off by ~100F. Maybe I'm missing something, but here's why I think that. Given the cook times are roughly accurate, the amount of black underside char on the first pie assuming a cordierite stone and somewhat frequent rotation is more like 750F. The last pie is more like 650 - 700F.
There is a lot of good news here. That burner really blows, so when moved to the side, your top heat is good. The underside char looks pretty uniform - which I translate to mean the stone is similarly uniform in temperature profile (or you rotated a lot). Either way, the uniform underside is a positive sign and "over-char" just means the temp throwing the pie was too high.
I think when you get that bottom temp dialed in, you're going to like the results.