In Box Cutter, Victor says he has learned how to cook Blue Sky by watching Walter. Walter responds that Victor doesn't know what he's doing and won't be able to deal with unexpected problems like a bad batch of precursor.
Not knowing anything about chemistry, Walter's rant sounded convincing enough to me, but it clearly came at least in part from a vested interest in keeping his job. Would Gus really have been remiss to let Victor copy Walter's recipe, at least until he could find a new professional cook?
Answers only from people who know what they are talking about, please.
Edit: I think people misunderstood what I was asking. Yeah, I know that other characters copied Walter's recipe and didn't reach his purity. What I meant to ask was, would Gus have been remiss to let Victor cook if we were just considering real-life chemistry?