I have a hard time believing that separating the gene that causes wobble would be impossible. But I think where the problem lies as Deborah kinda said, there is no way to tell which animals will wobble and when in their life they will. So you may be able to separate the wobble gene, but you would need advanced research to tell you first if it is separable, and second which ones don't have it. I'm not saying it's possible or impossible but it would certainly take more than simple selective breeding to separate it. And I'm pretty sure corporate lab is going to invest hundreds of thousands of dollars into researching spider ball python genetics. Until one of us hits the lotto I think we may just have to assume that if you get a spider you get wobble.