[Pontiac]

In one, stem cells derived from embryos are turned into sperm and eggs, which are combined again to produce successive generations of embryos, and so forth, with the idea of eventually generating people with an average IQ of around 300.

This I think may not be possible.

Consider that the naturally occurring humans of superior intelligence frequently end up as paranoid schizophrenics such as Uni Bomber Ted" Kaczynski

The architecture of the human brain may not permit the super intelligent to occur without adverse effects. Even the successful super smart in history have often had difficulties in everyday society. Nokola Tesla died alone and in poverty.

The human brain may simply be limited to average thinking by its design.

[tbw2]

There is also the drop off in marriage and birth rates for those with a graduate degree or higher, both male and female. And the increase in childlessness with high IQ and high educational levels.