The odds of producing normals go down too. Some people freak out about the long odds of producing the ultimate combo and forget this part. For example, if you had a pair of quadruple hets (lets say someone breeds an axanthic piebald to an albino stripe) then sure, your odds of producing the snow stripe piebald is only 1 in 256 per egg. But your odds of producing a complete normal (not het for anything) are also 1 in 256. Even your odds of producing normal looking animals go down to 81/256 (less than 1 in 3). So rather than only expecting about 1 /4 of your clutch to me morphs as when breeding single hets with quadruple hets you now expect over 2/3rds of your clutch to be at least one visible morphs and you could breed the pair for the rest of your life and still perhaps not see all possible combinations.