Is there any problem with consistently reciting Surat Al-Mulk during Salat al-Awwabin (the six rak'ahs after Maghrib), by dividing its verses among the rak'ahs, with the aim of ensuring its daily recitation to benefit from its virtue in saving one from the torment of the grave, given that this action is neither claimed to be a Sunnah nor are others invited to perform it?

Salat al-Awwabin (prayer of the oft-returning to Allah) is applied to the Duha prayer when the heat is intense, and to the supererogatory prayer between Maghrib and Isha. It has been named Salat al-Awwabin in some narrations, even if they are Mursal (having a missing link in the chain of transmission). The supererogatory prayer between Maghrib and Isha is recommended by many scholars. Acting upon a weak Hadith in such a case is permissible, provided that one does not believe in the specific sunnah of the number of rak'ahs or the recitation of a particular surah.