The QCT is defined as the text reflected in the consonantal skeleton of the Quran, the form in which it was first written down, without the countless additional clarifying vocalisation marks. The concept of the QCT is roughly equivalent to that of the rasm, the … undotted consonantal skeleton of the Quranic text, but there is an important distinction. The concept of QCT ultimately assumes that not only the letter shapes, but also the consonantal values are identical to the Quranic text as we find it today. As such, when ambiguities arise, for example in medial ـثـ ،ـتـ ،ـبـ ،ـنـ ،ـيـ etc., the original value is taken to be identical to the form as it is found in the Quranic reading traditions today. This assumption is not completely unfounded.You are right: the assumption is not completely unfounded, it is logically impossible, ‒ because there is no COMMON CONsonantal text. The "QCT" is not purely consonantal: ‒ there are letters for long vowels and diphtongs, ‒ there are letters for short vowels, the u in ulaika being the most common, but there are others: (26:197; 35:28) اولى , العُلَمَـٰوا۠ نَبَواْ (14:9 = 64:5, 38:21, 38:67) but (9:70) نَبَا Or ساورىكم (7:145, 21:37), لاوصلٮٮكم (7:124, 20:71, 26:49) Look at the 22nd word in 3:195 واودوا six letters, not six consonants, ‒ the alifs after final waw are no consonants but just end-of-word-markers. often اولٮك rarely وملاٮه (7:103 الأعراف١٠٣) وملاٮه ( bei dem man heute zwei stumme Buchstaben sieht: einen hamza-Träger und einen überflüssigen; ursprünglich standen die für (Kurz-)Vokale (a i, aʾi, ayi). Genau so ist es bei اڡاىں (3;144 + 21:34) IPak: افَا۠ئِنْ Q52: اَفإي۠ن In the common اولٮك waw stood for /u/; today it is seen as mute/otiose, because the ḍamma above alif stands for /u/. ‒ because there is no "Quranic text as we find it today" either. There is no rasm al-ʿUṯmānī either, i.e. not a single rasm, there are five or more. There are about 40 differences between the maṣāḥif written at the behest of ʿUṯmān. There must be almost 100 lists of these floating around, inter alia in my book Kein Standard (based on Bergsträßer GdQ3), and on this Turkish site, that is pffline now. The QCT can not be "identical to the Quranic text as we find it today" because there is no "identical Quranic text … found in the Quranic reading traditions today". You seem to believe that the qirāʾāt just differ in "the countless additional clarifying vocalisation marks". That's wrong. There are many books showing the differences between the ten readers, twenty transmitters and more than 50 recognized waysplus three multi-volume encyclopediae for the un-recognized readings. As there are many more differences than in ḥarakāt and tašdīd, and I just have to give some examples, to prove my case, I take them from Adrian Alan Brocketts Ph.D., words differently dotted in Ḥafṣ and Warš: ءَاتَيۡتُكُم ءَاتَيۡتنَٰكُم (3:81) تَعۡمَلُونَ يَعۡمَلُونَ (2:85) تَعۡمَلُونَ يَعۡمَلُونَ (2:140) (3:188) تَحۡسَبَنَّ تَحۡسِبَنَّ (4:73) تَكُن يَكُن (2:259) نُنشِزُهَا نُنشِرُهَا (2:58) يُغۡفَرۡ نَّغۡفِرۡ (2:165) يَرَى تَرَى ترونهم يرونهم (3:13) (3:83) يَبۡغُونَ تَبۡغُونَ يُرۡجَعُونَ تُرۡجَعُونَ(3:83) (3:115)يَفۡعَلُوا تَفۡعَلُوا يُكۡفَرُوهُ تُكۡفَرُوهُ (3:115) يَجۡمَعُونَ تَجۡمَعُونَ (3:157) (2:271) يُكَفِّرُ نُكَفِّر (3:57) فَنُوَفِّيهمُ فَنُوَفِّيهمُۥۤ (4:13) يُدۡخِلۡهُ نُدۡخِلۡهُ (4:152) يُؤۡتِيهِمۡ نُوتِيهِمُۥٓ What is true for the first four suras, is true for the rest. And what is true for these two transmissions, is true for all others. Okay, more than 90% of the words are the same in all transmissions, but that's not good enough to speak of a common consonantal text. It would be nice, when the Sultan of Oman (or someone else), paid Thomas Milo to make one muṣḥaf that represents sixty maṣāhif: ‒ a basic Common Quranic Text CQT with the possibility to make disappear: the vowel letters, and/or the end-of-word-markers, and the possibility to add letters specific to an old muṣḥaf (Kûfā, Baṣra, ) ‒ in a special colour to add diacritical points for transmissions ‒ in an other colour plus ḥarakāt specific to certain transmissions. plus assimilation marks, plus pause signs, plus ihmāl signs. Maybe even with verse numbers according to Kufa, to Ḥims, to Medina II … and one day even following MS. O....xyz ‒ God willing. BTW: The old grammar knows just letters/sounds/particles/ḥurūf,
          no con-sonants and sonants.
          It makes no sense to call Phoenician, Hebrew, Arabic
          letters "consonants."
          Only after Greeks used some letters ONLY for sonants/vowels,
          the other letters became con-sonants.
          As long as these signs function as end-of-word-markers (silent
          alif after waw, mem sofit, khaf sofit, many Arab end-letters),
          stand for a con-sonants or for a long vowel or for a short vowel
          or for a diphtong ‒ as in the qurʾān ‒
          there ARE NO "consonants", just letters.