Any kind of user customization will have the same effect. Any preference that the user can edit can be a confounding variable in an A/B test. I don't want to l

Any kind of user customization will have the same effect. Any preference that the user can edit can be a confounding variable in an A/B test. I don't want to live in a software world where as a user I'm forced into a one-size-fits-all approach to every interface just because it makes A/B testing easier.