I have 2 het pied males that I got from Peter Kahl. One has the "marker" and the other really doesnt. However, the one that doesnt is actually Spirit's (my female pied's) brother from a Pied to het clutch. So ...... It is definitely not a sure thing.
I can say this though, in talking to Peter Kahl about breeding the het males to normal females, his recommendation would be to keep females that had the marker to prove out and sell everything else. So I assume that he believes that there is at least some validity to the pied marker. He was also going under the assumption of breeding to 10 females, so in my case if we breed one of the het males to a normal or two this year we will keep all the females, marker or not.
Neil