Most nations that I am aware of that has B/Q requirments base it on proven ancestry of a person/people who are listed on their rolls as a tribal member. Thing is, traditionally there have been multitudes of "adoptions". Just because someone is on a Nations roll doesn't necessarily mean they are of that Nation by blood. I have heard, however, that some Nations do not recognise ancestry of an adoptee when it comes to deciding tribal membership in regards to the descendant.
Understood. It can get convoluted concerning B.Q. percentages. Instead of getting into that at depth, I segued into the whole 'where did people come from originally' contentious subject because that's something I've researched on and off over the years, (since that tangentially bears on the subsequent arguments about 'who got where first' and ancestry). As mentioned, it's a contentious and controversial subject. Some people get quite offended when it's even discussed, (let alone, debated). If you don't wish to discuss that underlying subject matter, I'd understand. If you do ...
What about those whose Chinese ancestors were from "Fou-Sang" in the Pacific Northwest from the 5th century? If there was a Chinese colony on the PNW in the 5th century, they might've had contact with the Tlingit, Makah, Nisga'a,Tsetsaut, Haida, Tsimshian, Gitxsan, Haisla, Heiltsuk,
Wuikinuxv, Kwakwaka'wakw, Nuu-chah-nulth, Coast Salish, NuxŠlk, Willapa, Chimakum, or Quileute. It may be that there are oral traditions related to any such ancient contact however, not that I'm aware of. http://www.geographicus.com/blog/rare-and-antique-maps/fou-sang-or-fusang-a-5th-century-chinese-colony-in-western-america/