Agree that codex is good. Don’t have experience with CC

Good points!!!

I guess the challenge is in knowing how much was it used and what for - editing and compactness or straight write-me-an-introduction.

I reckon that one challenge is that at the time of donation we will never know all undesirable mutations:( Perhaps the doses should be tested for known undesirable mutations before use.

As to too many doses per donor, if there are more donors the numbers per donor can be decreased.

Darn, too much to read;)

In deeper pedigrees, the estimand pertains to the founders of the population. In SNP LMMs, do you know who these are?

Genetic variance of a population is a random variable and not a parameter. It becomes one only if you condition on a particular population in space and time. Given this choice, the variance of other populations is still left as a random variable.

Lots in Evolution and similar journals, no?

This tells us that population structure itself, which does not contribute to "directional" allele frequency stratification, can't create fixed effects. What happens there is selection? well that I think is still an open question.
(8/8).

This makes PCs obsolete as a means to handle fixed genetic contributors. Of course, there are non-genetic contributors aligning with genetic factors so PCs might have role, but it has nothing to do with genetics.
(7/n)