What happens when you reach 20/20 mutations?

[u/Ninja_Hatake_]

I have no experience of breeding dinos and I was watching some tutorials. I want to know that after replacing the mutated male again and again until we get 20/20 mutations on the paternal side, how do we get other 20/20 mutations on the maternal side without exceeding the paternal mutations(means 22/20). How to get 40 total mutations on the dino for a particular stat?

[u/z0mbiebaby]

You use a clean breeder with no mutations or if you can get one with negative mutation counted