Is it permissible to perform the prayer of a vow (two rak'ahs) before the 'Asr and Fajr prayers instead of performing it after them, knowing that it is not permissible to pray after the 'Asr prayer or the Fajr prayer?

It was stated in Fatwa no. 48912 that the ruling on vowing to pray supererogatory prayers during disliked times, such as after Asr or Fajr, is that this vow is not obligatory to fulfill, nor is it considered valid by some scholars among the Shafi'is and Malikis. Therefore, it is preferable to abandon it.