If I owned this male I would not have a problem with using him as a breeder. I believe the chest is fine with the size of the bird. I think he has a nice shape Comb. Unless the SOP has been changed it says he should have a medium size head. Does look like his soft feathering might be a little brown tinted.
If a person wanted to get rid of the blended hackle you would need to use a little more of the Mahogany color.
Is his head the right size, or is it too small?