It seems to me that this is one case where more is better. The benefits of using a stone include both radiant and retained heat. If heat radiated from one direction is good, heat radiated from two directions is better. Also, because stones retain a great deal of heat, your oven is less subject to heat loss when you open it to check on something.
I use a HearthKit oven insert It's basically a 3 sided stone, lacking only the top. I never take it out of my oven. |