Thanks Iguana. The giant panda microbiome enables them to survive on a 99% plant diet despite having much more carnivorous physiology than humans, yet they do not have as optimal a mix of microbiome and physiology as healthy humans do (and tubers and certain other USOs also appear to be higher quality foods than bamboo). One of humanity's traits that appears to account in large measure for our success in populating and dominating almost the entire planet is our very diverse and adaptable microbiome and our mixed and adaptable physiology. The combination of a diverse microbiome with a mixed physiology and diverse diet appears to be far more adaptable than a 99% bamboo diet with carnivorous physiology and less diverse microbiome. Thus, changes in habitat are threatening giant pandas with extinction, whereas humans are growing even more in numbers.
Unfortunately, we have been damaging our microbiome, particularly since the advent of industrialization, urbanization, and antibiotics. Further damaging it by excessively restricting Paleo diets (such as with chronic VLC/ZC, veganism, and the Wai diet) where not necessary doesn't make a lot of sense to me.
Instincto, even when somewhat high in fruit (if not overly deficient in other foods), now seems more reasonable to me than chronic VLC/ZC. I can see now why GCB and other Instinctos turned away from very high meat intakes. That's not to suggest that Instincto is perfect. I suspect that many Instinctos excessively restrict diet biodiversity in other ways--such as avoiding the better starchy foods (and not just the bad ones). It sounds like you have not fallen prey to that as much as other Instinctos, which may help explain your long term success.
It may turn out that certain practices in meat-heavy societies, such as traditional coastal Inuit and Chukchi, help avoid problems from lack of plant diversity, though they are less practical in modern societies. It seems easier to develop a healthy diverse omnivorous diet in modern societies than a healthy VLC/ZC diet.
I should add that there are risks with starchy foods, and I'm not trying to totally discount those. I'm actually currently investigating one potential risk from a phenomenon known as persorption.