Is Imam al-Qastalani one of the trustworthy authors, and can his books, such as "Irshad al-Sari fi Sharh Sahih al-Bukhari," be used for study and citation?

Imam al-Qastalani is Ahmad ibn Muhammad al-Qastalani, of Egyptian origin, Shafi'i by madhhab. He was born in the year 851 AH and passed away in 923 AH. He was content, self-restrained, had a melodious voice when reciting the Qur'an and Hadith, participated in various virtues, was humble and gentle in companionship. He held beliefs inclined towards Sufism and showed a tendency towards exaggeration regarding the status of the Prophet, peace and blessings be upon him. Among his most prominent works is "Irshad al-Sari ala Sahih al-Bukhari." His methodology regarding Allah's Names and Attributes leaned towards the Ash'ari school, such as interpreting istawa (Allah's 'rising' over the Throne) as istila' (domination).

Despite this interpretation, it does not prevent taking knowledge from him. Scholars are just with those who err, clarifying their mistakes while praying for mercy upon them. It is just to warn against an error without diminishing the scholar's status and merit, for many imams erred in their ijtihad (independent reasoning), and this does not invalidate their status. Moreover, the Ummah has benefited from their works.