Is it permissible to perform supererogatory (nafilah) or sunnah prayers with the feet uncovered, given that uncovering them in obligatory (fard) prayers is not permissible?

The madhhab of the majority of scholars is that it is not permissible for a woman to uncover her feet during prayer, whereas Abu Hanifa and a group of Hanbalis permitted it, and Ibn Taymiyyah and Al-Uthaymin considered it the stronger opinion. The preponderant view is that it is obligatory for a woman to cover her feet during prayer, whether it is an obligatory (fard) or supererogatory (nafl) prayer, based on the hadith of Umm Salamah, which is not based on personal opinion, and the general principle is that supererogatory and obligatory prayers are equal in rulings unless there is evidence that differentiates between them.