Dragging my old post thread back from the dead. Thought I'd post the current state of my bakes. I'm still using the same (very) low temp home oven, but I'm now supplementing it with a small counter-top pizza oven. The counter top oven does a good job of cooking the underside so I start the bake there for a minute or so until I see a bit of charring on the underside, and then transfer to the regular oven where I have the top element set to full, the stone on the top rack, and have figured out a few little tricks to get the element to come on when I need it.
The result is getting me a lot closer to what I'd like - although this particular pie had barely a touch of underside charring, usually I go for a little more. The speed of the bakes has reduced a lot and the texture of the crust is worlds better than when I was just using the regular oven alone.