IMO, it seems that most herps in a small way are inbred no matter where you look. Species that collect in smaller "colonies", such as in montane species L.p.pyromelana and C. cerberus, tend to stick to smaller colony populations, and are mating more or less with aunts, uncles, sisters and fathers. They do not spread out and find new "bloodline mates." They stick to the same basic area, if not the same exact mountain slope they were born on. Even live most their lives in the same rock pile their whole life. This has been the way of life for many many years for these wild populations. As for C. atrox and others with wider homeranges, the "family genepool" is wider spread, so they may have mated with aunts, cousins and even wider "bloodlines" that these more localized reptiles have. Still, in the wild, there is not many problems when it comes to inbreeding, if any at all.
There are species that have been isolated from the mainland species they "broke from" 15,000 years prior, and are still going strong, and some have found new ways of adapting to seperate living conditions. But there is no proof even in these populations to suggest that inbreeding did any ill effects on their survival. They did what reptiles do best and that was evolve to better condition themselves for their new situation.
Now with beardeds, the American ancectors were just a handful of lizards, and now has broken out into many from those original parents. There is more of a controlled study group there to trace. But, it seems to me that there is no real hard evidence to show that these animals are doing poorly from this, and whats to say what would happen with new bloodlines introduced? If they have gone into a downword spiral from it, what would fresh bloodlines do anyhow? You would still see a strong introduction of these "manipulated" problems in the offspring. So what would be the point to breed new bloodlines to a weakened genepool?