When I had my porcelains and bred to lavender it was usually to lighten up the porcelain. You may get some pure lavs, but most will have at least some leakage in my experience. I got mostly porcelains of varying shades from this type of pairing. Porcelains have more of a variable shade and pattern. Also, since there is no standard everyone calls something different a porcelain, and they get them from different breedings. Some people have them pop out of certain BBS pens, some have splashing to them, and some are buffs diluted twice by lavender (this is the type I was working on). Some even have a penciling like a double diluted partridge. Right now it is really a work in progress with no set formula, or even an agreement among breeders of what to work towards, or what to call them.
I highly doubt if they are accepted it will be as a "porcelain" since there is porcelain in other breeds which required millie. Unless someone creates mottled, then millie fleur, then true porcelain silkies, which will look even different than the "porcelains" you see now. There are a few breeders working on this route too. fleur