breeding to determine a super form of a dominate gene would take years... especially if its female. Id say you need at least a solid three years of producing nothing but pinstripes to say it is a super. If your breeding a female figure it takes 2-3 years to get to breeding weight and another 3 years of breeding to prove it out (assuming your female goes three years in a row) your looking at 5-6 years to prove it out.
breeding sibling to sibling with a dominate gene snake would prove nothing. Dominant genes dont have a visual super form. The super form looks just like the "het" form ie. a pinstripe. The only difference is it does not throw normals, it throws all pinstripes.
I think you are confused by the term "super" this is not like co-doms dominant genes are hard and time consuming to prove out.