Abu Ja’far an-Nahhas (d. 338 A.H.), said in his book “‘Irab al-Qur’an”:

السلامة عند أهل الدين أنه إذا صحت القراءتان عن الجماعة ألا يقال: أحدهما أجود; لأنهما جميعا عن النبي صلى الله عليه وسلم، فيأثم من قال ذلك; وكان رؤساء الصحابة رضي الله عنهم ينكرون مثل هذا.

The path of safety for the people of (this) religion, when there are two Qira’ahs authentically (narrated) to the Jamā’ah, is to refrain from saying that one of them is better (or more superior) than the other, for both of them came from the Prophet (peace be upon him). The one who says this is sinful, and the heads of the Companions (may Allah be pleased with them) used to censure this.