Assuming mutation probabiity don't depend on the length of the copied DNA - copying 40 MB you will probably introduce 10 times more mutations than if you just c

Assuming mutation probabiity don't depend on the length of the copied DNA - copying 40 MB you will probably introduce 10 times more mutations than if you just copied 4 MB. only 10% of them will on average change the important code, so the end result is the same. So I don't see how NOP padding helps.