I did some more data analysis. Added Tibetans, etc. Since some readers have more opinions than I do I’ll leave commentary up to them. Two notes
1) The “Northeast Indian” group includes populations like Mizos (I know that from the ID codes). They seem different from Nagas, who are more Tibetan
2) No idea why Bangladeshis are showing so much “South Chinese” signal in admixture. Perhaps it is artifactual, or, we’re missing some donor population? There is clearly some Munda admixture in a few individuals, but it doesn’t seem to be the dominant contributor of East Asian ancestry.
Hoping for some illuminating comments.