What is the correct stance regarding the qunut supplication during the night vigil prayer (qiyam al-layl), and is it permissible to supplicate generally while prostrating?

The Qunut supplication in the Witr prayer is legislated, and it is permissible to add to it or use other supplications. There is a disagreement among scholars regarding its recommendation: some do not recommend it at all, some recommend it always, and some perform Qunut during the last half of Ramadan. Sheikh al-Islam Ibn Taymiyyah holds the view that the Witr Qunut is a type of permissible supplication, so one is given the choice between performing it or leaving it, as all of that is good. The Qunut supplication differs from the Qunut of calamities (Qunut al-Nawazil), as the supplication for calamities is made with words appropriate for the specific calamity. As for supplication during prostration, it is legislated and is one of the positions where supplications are answered.