Sometimes I have trouble explaining my point of view, and perhaps I misunderstand your ideas.. but this one seems straightforward..
You can breed all the CA imperator together and get imperator.. but you can't breed two different subspecies together and call them pure anything..
When you breed a Hog Island (imperator) to a mainland imperator or another island form of imperator you are creating products that could not occur in nature, whether or not they are of the same genus, species and subspecies.. in any discussion involving locality these can not be correctly termed PURE.
The same thing should probably be considered with mainland populations of imperator.. we can debate how much a boa in southern Belize may be different from one in western Costa Rica, or whether the terrain encourages or inhibits the free exchange of genetics and on ad-infinitum.. But in my mind a boa from Sonora or Sinaloa Mexico, bred to a Costa rica snake is also not any kind of PURE.
You can decide for yourself where to draw the line but I think it dishonest to say there is no such line, or point at which animals should be considered to be of different origin.
I'm not after an argument with you or anyone.. these are my opinions and they explain some of my philosophy about boa populations and how captive products should be viewed and catalogued relating to locality and the responsibilities of people interested in being in that market..
Personally I'm at a loss to understand what the importance might be of determining the locality or subspecies of a multi-generational MORPH project.. another fight about proprietory rights?
Good luck to everybody.

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Gus
A. Rentfro
RioBravoReptiles.com
www.riobravoreptiles.com
"Quality is not an accident. Perfectly healthy animals are a minimum requirement.. everything else is just salesmanship" gus