The problem with Mammoth Cave’s mineral output is more absolute.

The minerals are highly soluble.

Outside the dry cave environment, they do not slowly degrade; they dissolve.

A container of mirabilite left outside in a Kentucky spring rain would be a container of milky water within hours.

This has a specific implication for the central question of mineral use: even if the ancient communities of the Green River valley had maintained clear and specific practices for what to do with cave gypsum or mirabilite, and even if those practices had material expressions — ritual objects coated with gypsum, specific ceremonial vessels that held the minerals — those objects are not going to be found in surface archaeological sites.

The mineral coating or content would be gone.