Is it permissible for someone who has mastered a specific Islamic science, such as 'aqidah (creed) or hadith, to author books in it?

If someone has mastered a discipline and specialists in that field attest to their proficiency, then they may author works in it if they perceive a need, while observing the etiquette of authorship. Imam An-Nawawi mentioned that authorship aids in grasping the realities and intricacies of knowledge, and solidifies information, because it necessitates extensive research and review, and exposes one to the words of the Imams. He warned against authoring before being qualified, as that harms religion, knowledge, and one's reputation. He recommended refining a book before publishing it, and striving for clarity and conciseness of expression. He also advised that the greatest attention should be given to what has not been previously addressed, or that the work should be in an area of widespread benefit and frequent need. He concluded by emphasizing attention to the knowledge of one's madhhab (definition) (school of thought), due to its immense benefit.