I have a question for you, /sci/. Imagine that, out of the blue, a genetic engineering kit popped out of a rift in space and time, fully stocked with gene manipulation nanotechnology and other cool stuff from centuries in the future, stuff that makes CRISPR look like a DNA molecule LEGO model, what would you do with it in order to better the world, particularly improvements to humanity’s physiology (and NO, wiping mankind out isn’t a good answer, and no mind control or mental alteration pheromones or anything, please.)?

Hard mode: the changes have to be undetectable to a casual observer.