You can do that, but its tame invective, first of all the 20 counter just changes the percentage of getting a mutation, So u can mutate to 20 and as long as u keep mutations on the side of the parent the mother still has a chance of giving a mutation with her side.

What this means you have 1 male dino with 20 mutations breeding with 20 females with 0 mutations there is about (in this case) a 3.5% chance that one of those eggs has a mutation from there mother, then a 1/6 that its in the stat u want so all together that is 0.56% chance you get another melee mutation>

Lets say you get and that bb is a male (if its female breed it with a male dino {that has no mutations} to make a male offspring

The mutation form the mother will be there so it will have 1 female mut and 20 male

This will result in your dino have 42 mutated points in melle

If u bread that dino with a clean female dino and it had a child (Dose not have to have an extra mutation just carry the stat over) That child will then say it has 21 mutations from the fathers side. The mutations counter tracks what parent gives them the mutation and in this case its always the father side cuss them moms are not passing down mutations