It is an interesting thought. I know a zoo keeper whom has breed African Rock Pythons. He obtained one that was a lot less aggressive than he expected. armed with a temperament being genetic to some degree belief he went to a large us importer and as he tells it many many bites and hours of snake temperament testing came across a second A-rock that was also reluctant to bite. The second generation results are well against the grain so to speak. He has 4 young A -Rocks that are well very mellow animals, they are used in shows and have had thousands of kids climb and poke at them with no reaction on the snakes part. The offspring he has kept (many were sold to other zoos) have as of this summer (when we spoke last) never bite anyone outside the enclosure and only one bite at the home enclosure and at that was near feeding time.

I don't think that temperament is attached to a morph phase but it could be a genetic trait breed able like a colour trait. It seems that some breeders will often have a morph that is this or that but they may also be related to a single animal and that animals disposition has been passed along with that colour trait, a un related morph does not have the same temperament traits at all.

Pet idea I have no hard evidence for any of this but I actually would explore it if I had a larger collection, maybe in two years I'll try my calm male to the calm female I have and see if the offspring turn out to have easy going personalities too.