Is what is said about Ibn Muflih Al-Hanbali aligning with Tamerlane in the Tatar invasion of the Levant true, and did that affect his scholarship?

Summary of the Answer: The fall of Damascus to Timur in 803 AH was one of the worst historical events. The one who led Damascus in confronting Timur was the Chief Judge, Taqi al-Din Ibrahim ibn Muhammad ibn Muflih al-Hanbali (died 803 AH), who is not the well-known Hanbali jurist Shams al-Din Muhammad ibn Muflih, who had died before this event.

After the withdrawal of the Egyptian army, the people of Damascus resisted Timur fiercely from atop the city walls, which prompted him to resort to deception and offer a truce. The people of Damascus chose Ibn Muflih to negotiate with Timur, who deceived him with promises and claimed that he had freed the city as a charity for the Messenger of Allah, and that his true target was Sudun, the deputy of Damascus.

Ibn Muflih's return to Damascus coincided with his discouraging the people from fighting and his urging them to make peace, citing Timur's assurances of safety and his demand for the "Tuqzāt" (nine of each type of food, drink, animal, etc.). Despite some opposition, Ibn Muflih's opinion prevailed. He collected the Tuqzāt, then a thousand thousand dinars, then ten thousand thousand dinars (a thousand Tumans), and finally all the wealth of the Egyptians and the city's weapons.

After fulfilling all his demands, Timur seized Ibn Muflih and his companions, forcing them to draw maps of Damascus and its districts. He then divided the city among his emirs. The calamity and torment continued for the people of Damascus for 19 days, during which many perished from punishment and starvation.