>>281148218
>populations needs to maintain some degree of inbreeding to effectively reveal and eliminate mutational load
You conflating two disperate ideas. In large populations you want genetic diversity because that provides adapability. In small and unstable populations you want to maintain as much genetic diversity as possible while also pruning genes that might result in reduced fitness. If you were to reproduce with your second cousin that would have no meaningfull impact on the overal genepool, if a Przewalski's horse does that it might lead to genes that evolved over millions of years to just fade out of existence when they otherwise could have persisted.