They are the Skunk Va cut reversed. It's going to have a fair amount of variation in the gene pool regardless, because the plant is a poly hybrid cross to begin with. The only difference between an S1 and a traditional f x m cross is the variation you see in an S1 is the variation that exists in the mother plant, without any outside genetic influence. A standard cross introduces variations from an outside genetic source, the male.
A selfed clone does not by default indicate it is more stable or more representative of the parent. You still have to hunt for the right genetic traits.
dank.Frank