I assume most malawi peacocks are closely related. That makes them easier to breed and I assume without deformities.
I always knew blood parrots were hybrids, but deformities and apperence were result of selective breeding but from the other thread here, I was wrong. By seeing how short lived flowerhorn are through line breeding, I don't think/feel like mixing species that are very different is a good idea. Mixing among Amphilophus should be alright I assume, I wouldn't mind a midas and trimac only mix, get pearls and markings of trimac on gold color of midas, by selective breeding but without or limited inbreeding. May be adding a wild fish every or every other generations. Just speculations though.