Not long reining no, but that's a good idea too.
In the truest historical sense of lunging a horse should be taught with two people first not one, and in a straight line.
Remember lunging should be like leading, it's just more advanced and done from a distance. Also a horse should not actually bring any tension onto the line, therefore he should not be turning because of the rope, he should be turning because of you. In the same way, if you step out, so should he. When you can do that you can ask for anything, circles, ovals, 8s, D's etc. If there is resistance on the line (as the BHS teaches) then you are basically causing bracing , and even if you get past this the horse comes to rely on the tension which defeats the purpose and affects flexion and balance. BHS lunging is simply a way of teaching vocal commands with little consideration for the actual physical development of the horse beyond the aerobic.
If you do use a second person they must be just slightly behind you in timing so your cue is seen first, theirs is just reinforcement. Also when they halt they must also halt square and stand absolutely, and I mean absolutely still for a few seconds. Not even a shift of weight. As people we tend to find that the hardest part. I see so many people fidgeting around with mobile phones etc and expecting their horses to stand still, then the next second expecting the horse to be sensitive to every motion.