When it comes to treating metis born Garou, I know that from one side of the spectrum we have Children of Gaia/Bone Gnawers that treat them as equal, on the other: Fianna who see them as monsters and Get of Fenris/Shadow Lords who treat them as a weaklings and liability. But what about Silver Fangs? Imagine, that the two noble born committed such "incest" and such bastard is blemishing the honor and good name of the line. I believe that such children are usually smothered in the crib or at best send away. Yes, they can get back to the tribe...but then what about the Falcon - would the spirit admit that such offspring is one of his children?
Maybe I am wrong, but in my opinion Metis SF should be as rare as Silent Strider with access to Ancestors.