Will a Muslim regret on the Day of Judgment their negligence in performing some acts of worship, such as the Witr and Shafa prayers?

A Muslim should increase their acts of obedience in this world, because on the Day of Resurrection, they will regret their shortcomings and wish they had done more. Allah Almighty said: "{On that Day will man remember, but how will that remembrance avail him? He will say: 'Oh, would that I had sent forth [some good] for my life!'" (Qur'an 89:23-24), meaning he will wish he had sent forth good deeds for his true life, which is the Hereafter. It has been narrated that "If a servant were to prostrate on his face from the day he was born until he died of old age in obedience to Allah, he would belittle it on the Day of Resurrection, and he would wish to return to the world to increase his reward and recompense." One must beware of laziness in performing the Shaf' and Witr prayers. It is legislated to make them up for whoever missed them, and the majority of scholars hold that the Witr prayer is a Sunnah (recommended) and not obligatory.