Is the elided alif from the word "bismi" in verse 30 of Surat An-Naml considered one of the letters of the Quran, and what is the ruling on one who affirms it or does not affirm it?

This alif is not counted among the letters of the Quran because it does not exist in recitation or writing. It should not be written in places from which it has been omitted, as this would contradict what is well-known among the Ummah regarding its writing without an alif. Al-Marghini mentioned that the hamzat al-wasl (connecting hamza) was omitted from "Bism Allah" in Surah Hud, Surah An-Naml, and the opening of surahs due to frequent usage.