Maybe it has been said already, but I didn't see it.
Hybrids can be produced but usually you need to have the same reproductive cycles. I.e. Corns being egg layers and boas and puff adders being live. Don't think it will work even if you do artificially inseminate.
One that side note....
I wish I could work with E. Indigos but alas..the laws. I do have a 2.2 of Blacktailed Cribos (Central American Indigos)....and they are a heck of a lot of fun. Hoping to breed them this coming season although from what I've been told with Indigos...it isn't always the easiest thing.