Nice Demo. Thanks for sharing. Dakota Holes burn better when the hole is filled with fuel 80% and lit on top and allowed to burn down TLUD style(Top Lit Up Draft). You could have poked smoke/air holes down into the top of the fire pit diagonally to get a secondary burn of wood gases, turning it into a wood-gas burner, but your air feed hole would have needed to be a little longer. Rocks on the bottom prevent the fire absorbing water and he ground absorbing heat and focuses the heat upward.

I dont get why people make these they take so long