It seems as if what Ruy Llera Blanes and Galina Oustinova-Stjepanovic want to study are theists who are experiencing some kind of struggle about their theism. That’s fine, of course, but they ought to label their project accurately, instead of pretending to study atheists. Let them call this issue of Social Analysis something like Struggles Within Religion: Conflicted Theist Identities.
From what I’ve seen of this special journal issue on the anthropology of atheists, I’m not seeing the ground for building any single agenda for ethnographically studying atheist cultures.
The use of cradle boards and other apparatus with young children has been used at different times of human history to purposefully create elongated skulls, flattened skulls, bulbous skulls, and other unusual cranial shapes.