> The issue is where do you draw the line with 2)? What does "improve the genetic characteristics of your children" mean in practice?

That should be entirely down to the parents.

Someone having a genetically engineered baby doesn't affect anyone else.

There is no path that turns "I would like to terminate my pregnancy if the outcome is unfavorable" into "I would like to commit genocide on everyone whose genetics I do not like".

Granted, someone who already wishes for or aligns with the idea of ethnic cleansing might start by only publicly sharing their wish for the former to begin with, but I don't see a sensible argument for it being a natural extension of the former.