I understand those large fowl Chanteclers have some Cochin blood in their distant history, so am not surprised about stubs popping up in them.
The brown red Ameraucanas, both large and bantam, will sometimes produce offspring with stubs, but rarely in my own stock in recent years. But so do Wyandottes, Japanese bantams, and many other breeds. So I don\'t consider it a major concern. The important thing is to not mate two birds that both have stubs. For showing, the stubs are simply removed; I don\'t believe that is considered faking.
After having bred brown reds for more years than I care to remember, I can say with 99% certainty they will never breed 100% true to exhibition coloring by using nothing but exhibition colored breeders. That doesn\'t bother me because neither does blue, golden duckwing, birchen, and a number of other varieties in the standard. I realize these facts probably do relegate the brown red variety to one of the least popular of those that are recognized.