I had the same issue so I switched it out for a slab of steel. Holds the heat much better.
Using the OEM stone I’ve also found it important to make sure the stone is hot enough before the first pizza goes in (750+) and that the fire remains at full force during the cook (I have the old pellet version that requires a bit more fire maintenance). With these two conditions satisfied I can roll directly through multiple pizzas (we usually do 6-8).
I got my Ooni Hack turntable installed, works fantastic. https://www.oonihack.com/ have to turn down the heat now as the stone is much closer to the roof and heats up super fast.
I really would like to try this but my wife would kill me if I started messing with our Ooni.
If you get the OoniGear one there are no holes or mods to the oven at all. It clamps to the unit via a hole already there. The only thing is you have to get is a round pizza stone.
Crate & Barrel has ooni pizza ovens on sale this weekend (- 20%+). Ordered a fyra for $245. Other vendors may have the same pricing.
We love our Fyra, but there is a definite learning curve.
I use a metal, flat skewer to work the pellets after they get a good burn going.