It's true that the traditional P2P method of producing methamphetamine results in a racemic mixture of both dextro- and levo- enantiomers, which is less desirable as a drug. However, it's possible that Walt may have developed a method to produce nearly pure d-methamphetamine.

Walt's comment to Victor about stereospecific reduction suggests that he may have found a way to selectively produce the desired dextro- enantiomer during the reduction step. One potential method for achieving this would be to use an enzyme called ω-transaminase, which can convert amines into their preferred "right-handed" forms.

If Walt was able to use ω-transaminase during the reduction step of his synthesis, he could potentially produce a nearly pure d-methamphetamine product. This could explain the high potency and quality of his methamphetamine.

However, it's important to note that this is just speculation based on what we know about the traditional P2P method and Walt's comments. Without more information,