When you have a genesis kitty with A non genesis fur mother and a collection kitty father & the genesis kitty(kid) has the mothers fur hiding & has dads fur that's under the costume would you say that the kitten is hiding dads fur or would it be showing dads fur?
I think it's helpful if we just bracket LE Collectables with "Costume" and emphasize the idea of "costume".
In the scenario you mention above, the kitten is showing Dad's gen fur - which is, yes, hiding under the costume. But it's still showing Dad's fur. If you look at the kitten in pedigree it will list the true showing traits. The Costume fur doesn't count in the reckoning.