Is a person considered an appointed Imam if he leads prayers in an unofficial mosque whenever he is present, due to his intermittent presence there because of his work circumstances?

The regular Imam is one appointed by the Sultan or his deputy or the endower, or agreed upon by the people of the mosque. He has more right to lead the prayer than others, even if someone else is more virtuous. Therefore, if the people of the mosque are pleased with a person as their Imam, he is a regular Imam who has more right to lead the prayer as long as he is a reciter who performs the prayer well and knows its jurisprudence, even if he does not attend all prayers.