Is the issue of Murabaha to the one who orders the purchase, which some contemporary scholars consider impermissible, a matter of dispute? And what is the most preponderant opinion on it, along with the evidence?

You mentioned that the Sheikh said that promising to enter into a Murabaha sale for the one who commands the purchase (Murabaha li al-Amir bi al-Shira') is permissible. This is the view of some scholars, both ancient and contemporary. Ibn Rushd al-Qurtubi deemed it unlawful, while Ibn al-Qayyim permitted it. The Second Conference of the Islamic Bank, held in 1403 AH/1983 CE, issued a resolution allowing it. This opinion is the most preponderant due to the generality of Allah’s statement: (And Allah has permitted trade) [Al-Baqarah: 275], and because there is no apparent intention or form of usury in it. The general principle concerning transactions is permissibility.