I'm sure you've read Gwern's essay on polygenic trait inheritance. I'm not sure repeating the literature would be productive here. We have every reason to believe that embryo selection and genetic engineering more generally won't just "cure disease" but make us taller, smarter, more beautiful, and longer lived -- and there's nothing wrong with that.

Of course there's a lot of variability. At some point technology will improve to the point that denying the effect exists will seem ridiculous, although I'm sure plenty will try.

I will say, though, that downplaying trait inheritance and the way genetics is the mechanism for this inheritance produces models that don't predict reality nearly as well as models that incorporate hereditary via genetics, and especially when it comes to education, we're throwing public money down the toilet as long as we make policy using inaccurate models.

I don't know what any of the rest of this has to do with what I said. I ask again: are you writing all this by way of declaring that "heritability == DNA"? That's a straightforward discussion we can have. Why avoid it?