Why? What positive do you see from a lower conductivity at the cost of strength? I cook on these at traditional Neapolitan temperatures and get traditional Neapolitan results. I see no positive out of an even lower conductivity. With my experience and the data I now have on these If I could get them in larger slabs I would take them over Biscotto any day.
Jeff, I'm not willing to trade conductivity for strength. IF a particular chunk of Biscotto does actually clock in at .3 and will last, in a commercial environment for as long as a couple years, then I want that in a domestic option.
Now, bear in mind, my intentions go beyond Neapolitan oven owners. It sounds like your W-G bricks could very well be the perfect domestic solution for John Q. WFO owner. As far as deck ovens go, though, I have no idea that I'd ever find someone that needs .3, but if I can get a durable .3, I want it. A few years back, I thought steel would be more conductivity than I'd need, and, more recently, I thought aluminum's conductivity was most likely way too high, but now I see both of these materials very differently. As I consider .3, a part of me is saying that's ridiculous low and would most likely have no deck application, but... another part of me says 'you never know.'
Now that I see Tom's reference about Tuff coming in, on it's own, at .2 or .3, I'm pretty certain that .3 biscotto is a pipe dream. At this point, I'm not holding out much hope, but, if it turns out durable .3 can be done, I want it.
Btw, while we're talking about deck ovens, the best deck oven on the market, the Marsal MB, takes the top position because the low conductivity of the fibrament decks allows it to be be run at hotter temps while still maintaining good balance. The W-G bricks have even lower conductivity than fibrament, and, since you're using them with direct flame, they are most likely far more thermally durable as well. I, like you, would like to see these in larger sizes, but, other than that, these could easily blow fibraments out of the water and be the cornerstone for the next ultimate deck oven.