Can any cuckoo patterned breed be sexed by head dot?

[MontanaChickDoc]

I am picking up an izegem cuckoo hen and her chick tomorrow. I am not familiar with this breed but being a cuckoo pattern, will I be able to tell if the chick is a pullet or roo by its head dot?

 

[The Moonshiner]

Never heard of that breed either.
As far as sexing. Breeders I know that raise barred or cuckoo usually say accuracy is about 80%. I'd agree.
There seems to always be some that are clearly one sex or the other but then a few that are in the middle that could go either way. If it's just a single chick so nothing to compare it may make it more challenging.