That's great. Seems much of it is based on show and standards. I did skim through it, but, the fact remains that every different dog can/ or can not withstand various levels of inbreeding. Just a fact, so, it is impossible to exact a universal baseline, like a COI, that can be applied universally. I was on the Canine genetics forum for a short time with Helmuth Wachtal. Been on Armstrongs I beleive and a Jeffry Bragg. All big fans of assortive breeding at no more than 3%. Why did they hate inbreeding? Because they tried it and failed. Why? Choice of wrong stock, not seeing the signs that they needed new blood? Who knows, but, they couldn't get it to work. Maybe they thought these dogs should produce regular, large healthy litters. An amateurs view at best. The only book on dogs I have ever read was White Fang. The problem encountered reading articles like the one above, is that they put limits on everything. Problem is they cannot substantiate those limits. It is bull. Then comes along someone like myself, and others, that don't read all the crap, and they take it beyond what the scientists understand.
It happens because those people that don't read this stuff, don't know they aren't supposed to be able to do it.
Vets and many others say that inbreeding ruins the immune system. Trust me, nothing depresses an immune system more that all the vaccinations a dog gets from the vets. For the last 20 years I never had a dog at the vets, and, as inbred as my dogs are, they lived 30% longer without vets care. Not hard to explain is it.