The Ruling on Praying Behind an Open Sinner

This last question is from 'Abd al-Wahhab ibn 'Umar al-Murayhi, shared with him by 'Umar Siraj al-Mufrih al-Qurtubi from Morocco and Muhammad Na'if 'Awadh from Riyadh. He asks: Is the prayer valid behind a smoker if no one else is available to recite the Qur'an? We often see some people pushing each other, saying, "You pray," or "No, you pray," while one of them says, "I smoke." We ask for your guidance in this matter. May Allah guide you.
Answer: It is recommended to appoint the best and most proficient reciter among those present as the imam. One should appoint the best and most proficient reciter, based on the saying of the Prophet (peace and blessings be upon him): Therefore, it is obligatory to pay attention to this matter and appoint the best, then the next best. If some sinner, such as a smoker, or one who is undutiful to his parents, or one suspected of other sins, steps forward, the prayer is valid. The prayer is valid behind an open sinner... behind a sinner, according to the correct opinion of the scholars. However, the prayer is not valid behind a disbeliever; if his disbelief is known, the prayer behind him is not valid. As for the sinner, the prayer behind him is valid, whether he is a smoker or a sinner in some other way, such as being undutiful to his parents, severing family ties, engaging in riba (usury or interest) without considering it permissible... and so on. According to the most correct opinion of the scholars, the prayer is valid behind sinners. Ibn 'Umar prayed behind al-Hajjaj ibn Yusuf, who was one of the most sinful people and one of those who shed blood. Many of the Companions prayed behind some of the sinful governors. This indicates that the prayer is valid behind an open sinner. However, if the upright and just person is available, he is preferable, and he is the one who must be appointed. Those responsible for the imamate should appoint the best, then the next best, and should not appoint sinners as far as possible, as far as they are able. If a group of people gathers in a place at prayer time, they should appoint their best, their most righteous, and strive in this matter. This is what they should do, in accordance with the Sunnah and to honor it. Yes.