Do the variations between recitations reach the point where a word exists in one recitation but not in another?

The variation in readings, where a word or a letter appears in some but not others, is due to the word being present in some of the Mushafs (codices) written by the Companions but not in others. Examples include the addition of "من" (min) in Ibn Kathir's reading of Surat At-Tawbah, and the omission of "هو" (huwa) in the reading of Nafi', Abu Ja'far, and Ibn 'Amir in Surat Al-Hadid. This variation is because the Qur'an was revealed in multiple awjuh (ways/modes). When Uthman wrote the Mushaf, he was unable to gather all the readings into a single Mushaf, so he distributed them among different copies to preserve all the modes of recitation.