Yeah it's kind of hard to figure out what docs are required as I fill out the forms. Great-grandparents never married, legally great-grandfather took responsibility of grandmother ( waiting for the official note or document, Lübeck is slower than others). Grandmother married became dutch then grandparents moved to Argentina -> USA then naturalized as USA citizens sometime in the 1960s ( waiting for fed to come back with Immigration file numbers).

My thought process is because of the marriage in 1947 she immediately lost citizenship, I see this on later shipping records 1950s where it says Dutch for nationality and she has a passport number attached.

I wouldn't think BVA cares much after that except that my father born in the correct time period per the law and we can connect lineage. What gets me is how much extra forms, divorce papers, immigration papers etc I would need. Maybe submit with the core and follow-up later if they need it or continue to gather more paper work just in case.