I mean, you’re probably aware of this at some level, but fluffy dough is a problem in general, because gluten is the glue that normally traps the CO2 bubbles produced by the yeast.

They are reasonably successful with making somewhat-fluffy bread, but I’m guessing the thicker dough and not having toppings, which bring in moisture, helps a lot.

Having said all that, I’m also surprised that we haven’t found an alternative glue yet.