Is "A Treatise on the Affirmation of Allah's Elevation (Istiwāʾ) and His Being Above His Creation (Fawqiyyah)" by Abu Muhammad Abdullah ibn Yusuf al-Juwayni in agreement with the Sunnah and the methodology of the Pious Predecessors (Salaf as-Salih), and can it be relied upon?

Abū Muḥammad al-Juwaynī was a Shāfiʿī jurist who died in the year 438 AH. However, the treatise "Ithbāt al-Istiwāʾ wa al-Fawqiyyah" (Confirmation of Divine Ascension and Aboveness) attributed to him is not his; rather, it was written two centuries after his death during the Mamluk era, and its true author is Aḥmad ibn Ibrāhīm al-Wāsiṭī (died 711 AH).