Is it permissible for a congregant (ma'mum) to become an imam, and what are the proofs for this from the Qur'an and Sunnah?

Scholars have differed regarding the validity of praying behind a latecomer (masbuq) who becomes an imam, with two opinions: invalidity and validity. Those who assert its validity cite as evidence the permissibility of a follower (ma'mum) becoming an imam in the case of succession (istikhlāf), and the transformation of an imam into a follower in the story of Abu Bakr with the Messenger of Allah, peace and blessings be upon him. Sheikh Ibn Uthaymeen favored permissibility, but with disfavor (not being recommended), because it was not known among the Salaf (early Muslims). Therefore, it is preferable to avoid it. Consequently, the prayer is valid, but it is better to avoid it.