I recently read something on Reddit, I am not entirely sure if this rule is correct but, if it is, it changes a lot for me
The Racial Traits such as
Mostly Human - Undine
Pass for Human - Tiefling
Scion of Humanity - Aasimar
*To name just a few
With that trait, does that mean they now qualify for the Human FCB?
They count as human for qualifying for *anything*, including the human favored class bonus. Enjoy.
Those traits all change your type from (outsider(native)) to (outsider(native) AND humanoid(human)). So you are both aasimar (or whatever) and human, for absolutely all purposes.
It's the same deal as Half-Orcs counting as both orcs and humans. A long existing mechanic that is working exactly as intended.
And there is a feat called Human Guise that lets kitsune and skinwalkers do this too.