Is it permissible to prolong the qunoot in prayer by reciting some lengthy supplications such as Dua Abu…

Answer

In the name of Allah, if you are praying individually and have sufficient time, there is no objection to that. However, if you are leading a congregational prayer, you should not prolong the qunoot unless all the followers agree. Also, know that prolonging the qunoot in the Witr prayer after the Tahajjud prayer is recommended, and some of the prominent scholars would recite Dua Abu Hamza al-Thumali during this qunoot in the sanctuary of the Commander of the Faithful (PBUH). Allah knows best.