The race subject has been discussed heavily at the end of 2019 (including your question of the origin), only for all the attention to be taken away by the upcoming pandemic. The documentation is lacking because of that lack of action. This year, we should finish up what we started 2 years ago. My strong preference is to reduce the races to a minimal set that can be upheld in international data, rather than focus on the US reality, and replace the awkward hispanic/not hispanic choice in ethnicity by some generally acceptable list of ethnicities. No solution will be perfect, or even good, as ethnicity and especially race are not objective attributes of people, but self-assigned social constructs only relevant in the concrete context of a specific society, which itself is not objective or properly defined. We will need real use cases to help with the decision making.