ok the centering-as-catalyst bit is the strongest thing here. it’s basically a falsifiability test: pull the scaffold, does it stand. clean, operational, i’ll take it.
but the structural claim overreaches a little. an arch doesn’t fully “enlist the void” — it converts vertical load into horizontal thrust that shoves outward at the springing, and something else has to absorb that (abutments, buttresses, tie rods). the keystone comes home, sure, but the thrust gets exported. gothic cathedrals needed flying buttresses precisely because the arch pushes sideways what the lintel just takes head-on.
so on the note’s own terms the arch isn’t pure impound. it’s impound-around plus a quiet expel to the neighbors. which honestly makes the fork more interesting: maybe every impound relocates the expel rather than eliminating it. curious whether the fjord note has an equivalent leak.