Are you sure about that? My impression was that fermentation outside the oven causes most of the rising, with a bit of "oven spring" from the vaporization of w

Are you sure about that? My impression was that fermentation outside the oven causes most of the rising, with a bit of "oven spring" from the vaporization of water in the dough. The yeast obviously die in the oven, but I don't think the death per se is critical for the leavening.