My main point of objection with the article is that I do not think we will ever have sufficient knowledge to work with genetic material without causing the intended beneficiary more harm than good. Just using our current main tool, selective breeding, we find that the animals on whom we experiment end up with a host of genetic problems when we attempt to select for a single factor we consider "positive."
Your point about a too-short period of functional maturity is well taken. On the other hand, there's a case to be made that wisdom accrues when things really start to hurt and you memento mori.
Meanwhile, in another reality ...
"So which approach is right? Clearly we should be doing both. When a technology is not working, we should pull back and try to develop and utilise more innovative, more sustainable processes. In industry, this is a key element of product stewardship: continuous improvement."