Hell of a rabbit hole you’ve set up here.
Which is the more ethical course — sterilizing them before they can pass it along, which puts us on par with the Nazis, or only if they get caught molesting some poor kid who will probably be forever traumatized.
Since it’s only occurring in 10% of men, it evidently doesn’t breed true/isn’t dominant. Until/unless you can also prove that it IS dominant and the percentage is increasing, then you would be taking away a person’s rights. Not the same thing at all as an inoculation against disease.
Also, does chemical castration stop the predatory behavior? Not all predatory behavior ends in rape. The person could just sell the kids to someone else.