Prozzak would have been invented 1000 years ago.
....but would only be available to witnesses on the black market. The education thing would not be an issue anymore because the excuses of not associating with worldly people would be gone, and the pressure to go on field service would be less too because there would be less people to preach to. Pioneering would be discouraged because that would take all the ministry up for yourself and not let others have a share. And kingdom halls would remain the size they are now because any larger would prove too difficult to control.