Holes in native structures weren't constructed to vent tobacco smoke, they were to vent cooking fires. Chain smoking wasn't a use that Indian tobacco was put to pre-Columbus. That was learned from colonizers who took something sacred and turned it profane.

Well GUEST, the smoke holes obviously vented both - the cooking fires and the burning/smoking of ceremonial Tobacco, sagebrush, sweetgrass, cedar and other sacred herbs which were (and still are) regularly used.