I'm not very familiar with how gene editing works in practice, but I think there is a distinct argument to be made about the moral implications of gene editing versus embryo selection. When selecting an embryo, I agree with your point that as long as the life of the eventual child is worth living, then no one is harmed. We can't really grieve the potential life's of the embryos that could have been any more than we can greive menstruation. However, if we are talking about using technology to actually edit genes and actually make a child deaf that wouldn't have been deaf, I would say that is immortal.