What is the ruling on writing the tanwin of fatḥah in the Holy Qur’an on the alif instead of the letter preceding it, in a way that contradicts the script of the Muṣḥaf?

Placing the fatḥah tanwīn on the alif is not considered contrary to the Uthmanic script of the Qur’an, because vowelization (tashkīl) of letters is not part of the Companions' divinely ordained script (Uthmānic script); rather, it is a product of the ijtihād (independent reasoning) of the Tābiīn (successors). Placing the tanwīn on the alif instead of on the letter itself is the preferred view among specialists and is practiced by the North Africans (Maghariba), because the وقف (وقف) occurs on it, as mentioned by Al-Kharrāz in "Mawrid al-Ẓamʾān" and by Al-Shanqīṭī in "Kashf al-Amā wa al-Rayn."