That would be one of my major concerns. Using 3rd grade nucleus would be very risky, but if it works as purported, quite a strain would be lifted from the species, and nucleus cost would drop from $45,000 (per million) to around $12,000.
I had quite a long conversation with Mr. Cross about the method. And the color and reflectivity traits are their strongest with the vapor method.
http://www.islandpearls.net/newtech.htm
We may have to try a portion with one and a portion with the other in a sort of controlled experiment. But if it works perfectly, we would be 2 years behind the Japanese farmers who would do nearly anything to pull away from the brink of extinction where they are today.