“Of course, that is done from a basic framework of US law...”
Well, that is the key. If we pass a law that takes into account the parent’s citizenship status in another country, then the citizenship is still being determined by OUR laws, not by the other country’s laws.
If citizenship is truly based on other countrys’ laws, then what is to stop Canada from declaring anyone a “Canadian citizen” if they wish to stop them from being elected President? Absolutely nothing! Any podunk country on the planet could pass an edict and influence our elections if we did things that way.
The flip side of that is what is to stop the US from declaring anyone a NBC of the US if Congress wants everybody in the world to be eligible for the presidency? Is your answer the same, "Absolutely nothing!"?