The lack of copper metalworking in the Central American area might have something to do with the lack of copper.
I doubt these traders mysteriously sailed direct to western Mexico and miraculously found they had reached another copper rich area.
In all probability, the rafts followed the coast for years, extending their range and trading as they went until they reached the copper rich areas.
Copper chisles played a major role in Captain Gray’s late 1800’s trade with the Pacific Northwest indians.
Late 1700’s, Late 1700’s