Hard disagree on that. I'm sure anyone who's played Humankind would see why. You'd either have to make uniques weak to the point of being insignificant, or each civ would constantly spam their uniques. Even in its current iteration, VP suffers a bit from a lack of diversity in city-building (i.e., you end up building everything in every city). With more uniques, it would get even more samey. Plus, there's the inevitable yield inflation and the impossibility of balancing it, it kills the fun and challenge of power spikes too. Humankind has some good aspects and could have been much better with proper dev support and modding tools, but the core gimmick (new civ and new uniques each era) is just so bad, and there's no saving it.
Aaanyway, back to the topic, I might contribute to 2UC when the time comes, as I often prefer simplicity and symmetry. But who knows? If the game does end up feeling like Vern's AI tests with new UCs making civs more well-rounded, there might not be a need for that.