I got a harvard invitation interview very early in the cycle (November) with below both median numbers as a non-URM. That happens pretty rarely, especially so early on in the cycle. I don’t think I would have gotten the invite without 7Sage’s help.
Also, there's some webinars talking with another non-native speaker Sage by the name of Nader. Under Resources go to the one called "Our 89 Point Increase Story" to hear about him and three other former students' experiences.