I had this same idea and I think it would be a cool project. Since I love my snake's personalities far more than their markings, this is the kind of breeding that would really interest me.

I think there are some unique challenges. Unlike morphs, the results are hard to quantify. This would make breeding selection and pricing very difficult. There is also a significant chance that genetics can't guarantee a certain personality profile. I believe it probably has a large impact, though.

At the very least, such a venture would have to produce fairly dramatic results to compensate for the fact that its very subjective. For the same reason, I think it would be very important to stick with it and build a brand name that people trust.