Yes, I think height is a heritable trait.

Understanding whether the model is capturing biology is critical when thinking about applying it to IVF. If the model is primarily capturing socioeconomic correlates, those factors will (in most cases) be fixed for all embryos from a given pair of parents. The PRS needs to be weighting _biological_ risk conditioned on a fixed environment if its to be used ethically in this context.

What are your requirements for ethical use?

In what case are you expecting the purchasers to be harmed? It seems reasonable to screen for the other factors as well if a correlation exists.

There may be but “nature” is strong on atleast this trait. Just look at height differences between north and South Koreans.

North vs South Korea would be an example of nurture/environment, not nature/genes.

An example of Nature would be comparing well fed children of basket ball players vs children of horse jockeys.

I suspect that was a mistype based on their other post, it was probably meant to be "nurture"?

Yep, nurture definitely. Can’t edit it anymore.

Nature can still be important for even highly heritable traits. For example, the size of a person's vocabulary is highly heritable, but a feral human will have very limited vocabulary. Such traits still have a very strong biological basis.