This technique has no possibility of being used to manufacture children with specific traits, other than being free of mitochondrial disease. All specific traits are coded on nuclear DNA and heritable from either parent (except male gender, which requires the Y chromosome from the father). Mitochondrial DNA is an entirely different thing.
So, you think that we can’t figure out the rest? Or do you think that, if this manipulation becomes accepted and commonplace, we can still prohibit other manipulations, simply because they aren’t the same type of manipulation?
Do you give no weight to the “slippery slope” argument, or do you simply not mind if we go down that slope?