I wouldn't worry so much about limited gene pool, at least not with the dominant/co-dominant mutations. Even the recessive get outbred and crossed. It's the possibility of unknown effects other than skin deep that might cause shorter lifespan. Apparently the spider mutation causes the spider appearance AND a tendency for wobble. A tendency for kinking seems to be part of the caramel and cinnamon/black pastel mutation. Hopefully most of the mutations are only skin deep but maybe there is a morph out there that causes a tendency to tumor or internal organ failure within 10 years.

I actually worry about the ones that are still rare and expensive after a long time. I was starting to wonder what was up with caramels not being more common so long after they first showed up before the kinking issue came out. But looking at how stripes have dropped in price recently I'm figuring they are likely a very robust easy breeding animal. Probably the market is not the best barometer for morph health but without connections maybe something to look at.