I wouldn't ride my bent without my helmet mounted mirror. It is too awkward to turn and look back when reclining in the comfi seat.
I was on a tour in British Columbia a few years ago. The road we were on had a very narrow shoulder with a rough pebbly surface. Because I had my mirror I just rode in the middle of the car lane and only moved over when I saw a car coming. It was perfectly safe because I could keep a constant watch behind. After awhile the wedgie riders around me would ride in the car lane and I would warn them if a car was coming which took a lot of trust on their part.