Mark you forgot to answer one of my questions from earlier.
Also, do you feel that you are getting equal top and bottom heat during a typical bake? I mean are you happy with the top browning or do you want it to brown more or faster?
When baking at a hearth of 900F, are you still getting excessive bottom charring despite using the iron spacers? Approximately how fast are your pies baking at 900F hearth temp?
If you haven't tried already, I would to fashion a small heat deflector mod as I recommended earlier. See reply #12
"I do see that there is some sort of baffle/heat deflector to send the heat up towards the ceiling but IMO, this piece has to extend a bit further and then curl back towards itself to some degree. This will help concentrate the flame back towards the crust."
You can make one out of a small piece of sheet metal or some sort of SS flashing. Put a small bend in it and tuck it under the top stone, between the top stone and the built in baffle. That will redirect the heat back towards the crust to provide better top browning.