i listened to an interview with kevin mccurley from NERD where he expands on lethal combos... and he mentioned that he has to euthanize several of these each year... he doesnt even try to raise them up. i consider that deadly. when a big breeder with that amount of experience gives up on it and euthanizes each super champagne that hatches, that speaks volumes. it strongly implies that attempts to get them to reproductive age will fail.
also, enchi champs are just too pretty to not go for the combo if there is a chance to produce them. its not just that champ x champ is ill advised, its also that enchi x champ is really nice and definitively a bonus.