I must respectfully disagree.
As many years as the Spider morph has been around, don't you think numerous people have tried this? If it were possible to selectively breed it out, it would have been done by now.
Unlike a color morph, the wobble seems to be a genetic defect tied to the Spider gene itself, which is why ANY snake that carries the gene can wobble. Spiders, Bees, etc.
I have also recently heard of non-Spiders who do it, so I don't really believe selective breeding will work.
Gale