Let's say I have an interview with 3 people. Each interviewer does self-introduction followed by よろしくお願いします. When they say it I say it too, kind of, in response. Then I say my self-introduction and say the phrase. Then we start to discuss different topics and sometimes I feel it is a right moment to say it again.
My question is when is the right time to say it? Do I say it each time interviewers say it? Do I say it only at the end of my self-introduction or it does not matter and I can say it whenever I feel like it without any penalties?