How reliable is Dr Jonathan Brown of Yaqeen Institute in his research?

He is prone to errors. Here's an example from an article he wrote on https://yaqeeninstitute.org/jonathan-brown/the-fate-of-non-muslims-perspectives-on-salvation-outside-of-islam/ Look at the section citing footnote 15. The famous Salafi scholar of Yemen, Muqbil al-Wadi’i (d. 2001), concluded that the answer was no, and that the people of the US and Europe were a modern Ahl al-Fatra.[15] Muqbil bin Hādī al-Wādiʿī, Majmūʿ fatāwā al-Wādiʿī, ed. Ṣādiq Muḥammad al-Bayḍānī ([No place, no publisher], 2005), 414. Here's what Shaikh Muqbil actually said https://muqbel.net/fatwa.php?fatwa_id=3158 هل يعتبر الكفار في فرنسا وبريطانيا وأمريكا وغيرها من أهل الفترة، مع أن عندهم شيء من العلم والمعرفة عن الإسلام، فمثلا يعرفون أن من أركان الإسلام الشهادتين والصلاة.. الخ، وأن الله واحد Are the general disbelievers in Europe and other than it (considered) from the people of Al-Fatrah? Question: Are the disbelievers in France and Britain and America and other (countries) considered from the people of Al-Fatrah, even though they have some knowledge and awareness about Islam, for example they know that from the pillars of Islam are the two testimonies (of faith), and prayer, etc. and that Allah is One, so what is the ruling (about them)? Answer: The people are different in that regard, and the disbelievers are different in that regard. For there are some of them who know the reality of Islam so they are not considered from the people of Al-Fatrah. And some of them who did not know the reality of Islam, and did not know the Prophet (peace be upon him), and I think the brother who is asking is living among people who have knowledge about history, otherwise there are in some disbelieving countries those who do not know anything about Islam. And he doesn’t know anything about the Prophet (peace be upon him), and they don’t know except (what makes them) repulsed about Islam and (what) makes it hated to the disbelieving European society, or other than it. So the likes of those, we hope that they are included in the saying of Allah: And never would We punish until We sent a messenger. [Qur'an 17:15] And the saying of Allah: And Allah would not let a people stray after He has guided them until He makes clear to them what they should avoid.. [Qur'an 9:115] (Majmu’ Fatawa Sheikh Muqbil bin Hadi Al-Wadi’i, p. 414.)