All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
There is no harm in reciting some words with a confirmed recitation other than the recitation of Hafs, and the prayer is valid with that.
Shaykh Ibn Taymiyyah said, "It is permissible to recite some of the Quran with the narration of Abu ‘Amr and some of it with the narration of Naafi’, whether this is in the same unit of prayer or two different ones, and whether this is inside the prayer or outside of it."
However, it should be noted that the one who applies Ibdaal (i.e. changing the letter Hamzah into Madd [a long vowel]) in these words is Abu Ja‘far and Abu ‘Amr. As regards Warsh, he has two narrations for it; one of which is the narration of Al-Azraq, and in this narration, he does not apply Ibdaal in the words الشأن and البأس; rather, he only applies it in the word الذئب.
The second narration is the narration of Al-Asbahaani; in this narration he applies Ibdaal in the word الشأن and الذئب, but he does not apply it in the word البأس according to the most correct view.
Al-Jazari said in An-Nashr fee Al-Qiraa’aat Al-‘Ashr (1/391):
"Abu Ja‘far recited by replacing the silent Hamzah with a prolonged vowel according to the vowel that is before it, if it is Dhammah, he changes it with واو, and if it is a Kasrah, he changes it with ياء , and if it is Fat-hah, he changes it with ألف ... Warsh conforms with him from the narration of Al-Asbahaani about Ibdaal in all words of this category, and he excluded five names and five verbs from this: the names are ...
Ibn Mahraan narrated a different view from Hibatullah, as he did not exclude anything but only two verbs (ذرأنا - تبرأنا), with a difference of opinion, but this was a mistake in his narration. Also, Al-Huthali did the same, as he did not exclude the verbs, and As-Safraawi was the only one who excluded (يشا، ويسوهم، ورويا), as he reported a difference of opinion about this. I think that he took this from the statement of Abu Ma‘shar At-Tabari, but it is not as he understood, because Abu Ma‘shar stated that the Ibdaal is applied in it... and Allah knows best.
As for the narration from Al-Azraq, then he replaces the Hamzah if its place corresponds to the place of فاء (the first root letter of the word [note that the stem of any Arabic word is formed of three letters فعل), such as (يومنون، ويالمون، وياخذ، ومومن، ولقانا ايت، والموتفكات) but he did not replace the Hamzah that corresponds to عين (the second root letter of the word) with the exception of (بيس), regardless of its position and (البير، -الذيب), and he pronounced the Hamzah clearly (Tahqeeq) in all other words ...."
Allah knows best.