Good to know this, I have Project Wheaten Crele Orpingtons I'm working on, & currently working on breeding out yellow skin, & doing some comb, body type, tail shape/angle corrections. I'm breed towards SOP. Same with my silkies. I have SQ silkie breeding stock I've been using.I'd say yes to both. You can't enter a bird with completely random colouring, but if it's a discrete colour pattern that we can judge based on qualifications, then yes.
The tricky part is I'm using hatchery stock, & breeding the bad traits out. I'm getting there though.