[edit: existing polygenic screening companies might not read enough genes to do this. Although it would be easy to offer a more complete service that reads most genes, banning the more complete version might be one way regulators could prevent this otherwise hard-to-prevent thing.]
What about IQ? There are definitely scientists who have figured out how to do polygenic analyses to predict a modest amount of variation in IQ, though I don’t know if their algorithms are public, and they’re certainly not convenient for amateurs to use. If you had them, would they work? Gwern has done some calculations and finds that with ten embryos (a near-best-case scenario of what you’re likely to get from egg extraction) and modern (as of 2016) polygenic scoring technology, you could get on average +3 IQ points by implanting the smartest. If polygenic scoring technology reached the limits of its potential (might happen within a decade or two) you could get +9 IQ points. Embryos from the same parents only vary a certain amount in IQ, and about half of IQ variation is non-genetic, so you can’t work miracles with this (if you want to know how to work miracles, read the rest of Gwern’s article).