I came here to suggest this same feature and like @riddley, I had not considered the security implications. It would be possible to ask the user to verify each of the domains in the inclusion list before saving with a very stern warning. That would not be a great feeling and would put a lot of work on the users plate.
Perhaps, the lens could be published to some site and then we could use a "crowdsource" model to vet and vote and verify. Maybe the lens would need some number or level of verifications, almost like a code review on Github/Gitlab, before it would be available for others to add to their own settings.