Mystery, I do respect you, but no.Buff Orpingtons were the first birds I practiced wing Feather Sexing, & it's been accurate.
Males presented Even Over Lapping coverts, & no visible primaries at 5 days old. The coverts are all short, & rounded.
They're slow to feather out, usually grow in their tails later, or remain shorter for a few weeks. They usually get their comb, & wattles early, & pink up.
Females have long primaries, & short primaries that create a long, short, long short type feather pattern when the wings are spread out at 5 days old.
They feather out a bit faster, grow in their tails before the boys, & their combs, & wattles stay small, & pale.
Hey, don't doubt my experience with this type of thing. I've been sexing chicks this way for a couple years now, self trained. I didn't use Wikihow.Mystery, I do respect you, but no.
I have no reason to believe feather sexing works on any standard breeds. Maybe some varied and subtle growth differences, but not ‘wing sexing’ as all those Wikihow sites would have it.