Is it disbelief to believe that the word "musaytir" in the Quran could be a scribal error from the writer, and not from God?

It is advisable to disregard misgivings related to disbelief (kufr), for mere thoughts and self-talk are not blameworthy and do not constitute disbelief, as the Prophet, peace and blessings be upon him, said: "Indeed, Allah has pardoned my Ummah for whatever thoughts occur to their minds, as long as they do not act upon them or speak of them." It is not permissible to accuse the writing of the Mushaf of error. The Uthmani Mushafs unanimously agreed on writing "Musaytir" with a "ṣād" (ص), and this is a consensus that must not be contravened. Reading the word with a "ṣād" is firmly established, multiply attested (mutawatir), and consistent with a valid facet of the Arabic language. Its writing with a "ṣād" was for the wisdom of combining different recitations.