Notes & justification
In both occurrences of ٱقْرَأْ (āyāt 1 and 3) Abū Jaʿfar turns the sākin hamzah into a madd letter — ٱقْرَا — in every position. Ḥamzah does the same, but only when stopping on the word. Khalaf al-ʿĀshir departs from the reader he otherwise follows (Ḥamzah): he keeps the hamzah in waqf and does not use the sakt. Warsh has no ibdāl here, because his ibdāl of the sākin hamzah is confined to a hamzah that is the fāʾ of the verb, and in iqraʾ it is the lām. Al-Sūsī has none either: iqraʾ is one of the words expressly excepted from his general ibdāl of the sākin hamzah. The couplets: the Durrah's line on Abū Jaʿfar's ibdāl of every sākin hamzah except in anbiʾhum and nabbiʾhum; the Shāṭibiyyah's line on Ḥamzah's waqf, where a sākin hamzah becomes the madd letter of the vowel before it; the Durrah's line on Khalaf al-ʿĀshir keeping the hamzah in waqf and dropping the sakt; the Shāṭibiyyah's line limiting Warsh to the hamzah that is the verb's fāʾ; and al-Sūsī's rule with its list of exceptions, among them iqraʾ in its three places.
Change it, from him (Ḥamzah, stopping), into a madd letter when it is sākin — the letter it becomes is dictated by the vowel before it.
When a hamzah that is the fāʾ of the verb is sākin, Warsh shows it as a madd letter, changing it.
For al-Sūsī every sākin hamzah is changed to a madd letter — except the jussive, which is left alone …
… and hayyiʾ, anbiʾhum, nabbiʾ in four places, arjiʾ in both places and iqraʾ in three: take note.
Its sākin (hamzah) pronounce in full, protecting it (Khalaf) — and change it (Abū Jaʿfar), except in anbiʾhum and nabbiʾhum: not there.
… and sal with fa-sal spread (Khalaf); and give the hamzah in waqf in full, and he left the sakt aside.