Is Al-Insaf fi Ma'rifat al-Rajih min al-Khilaf by al-Mardawi al-Hanbali considered among the books of the preferred view within the Hanbali school of thought, or across all schools of thought? And what is a book of preferred views across all schools of thought that would be beneficial?

The book "Al-Insaf" by Al-Mardawi Al-Hanbali clarifies and favors the relied-upon opinions within the Hanbali school of thought, and it does not address the opinions of other schools. There isn't one single predominant book in every school; rather, there are multiple authoritative books that elucidate the favored and relied-upon positions, despite some existing differences. There are books written as introductions to understanding the schools of thought and their respective texts. Among them, in the Hanafi school: Muhammad Bakhit Al-Muti'i's treatise; in the Maliki school: Nazm Bu Talayhiyya and Al-Madkhal by Ahmad Dheeb; in the Shafi'i school: Al-Fawa'id Al-Makkiyah by Al-Saqqaf and Al-Fawa'id Al-Madaniyyah by Al-Kurdi; and in the Hanbali school: Al-Madkhal by Ibn Badran and Al-Madkhal Al-Mufassal by Bakr Abu Zayd.