Gains of several standard deviations in mental traits, including intelligence, are looking very plausible with minimal technological progress. We are well past the speculative phase.
As we live in a competitive technological landscape and China, Korea and India do not share our taboos against genetic enhancement, we will be forced to embrace this, too.
Tar and feathering human enhancement as “eugenics” worked when human enhancement was not possible. We no longer live in that world. The signal is no longer cheap. Whatever nations fail to embrace embryo selection, iterated embryo selection, and eventually genetic engineering for intelligence will find themselves as children, competing in a technological landscape they are too dull to understand.
Like Lysenkoism of old, our modern mental Lysenkoism will become unsustainable. We would be wise to discard it now.