Interesting! Could you point us towards where the "Very good arguments have been made that the Enlightenment (or Age of Reason) did originate from native North American ideas and ideals" can be found?
The Native American democracy that the U.S. founders were most likely to know about was the Iroquois Confederacy.
and from other native groups you'll see many statements like:
~ https://collegefund.org/blog/democracy/democracy-is-rooted-i...
IIRC there's a lot of material about the North-North-American fur trade origins piggybacking onto existing Great Lakes and other regions trade networks with the French and the British picking up political and trade habits from those peoples.
( Not a scholar in the field, just a broad reader )
Be aware that the book is a bit academically written and that they want to cover every base in each sentence instead of writing clearly to the point. So sometimes it is extremely interesting and sometimes frustrating and boring.