What is the ruling on praying behind an Imam who performs qunut in the Fajr prayer every Friday, and is it permissible to pray behind him even if it is a supererogatory prayer, such as the nighttime prayers of Ramadan?

Scholars have differed concerning the ruling on reciting qunut in the Fajr prayer every day. The correct view is that it is a reprehensible innovation (bid‘ah makroohah). What the imam is doing is an innovation that has no basis, and he should be advised to reconsider his action. As for praying Tarawih behind him, there is no objection to that, because his qunut in Fajr has no connection to it, and he recites qunut based on an interpretation. Sheikh Ibn Baz permitted seeking out mosques in pursuit of a beautiful voice of the imam and a sense of humility (khushoo‘), if the intention behind that is to seek help in achieving khushoo‘ and presence of heart, and not merely out of whims and wandering. So, a sound intention makes this action permissible.