Good reminder. That's why I wear a vis-vest, and always sound my AirZound when coming alongside and passing trucks.
I only drive the company truck(s) part of the time, and only straight truck (no trailer, we have another guy for that) but to me, I see too much of the truck's cab in the mirror at the very beginning.. I'd have the mirrors a little farther out, so I could see the edge of the truck in the inside edge of the mirror, and be able to see where the rear wheels are. That looks like almost a quarter of the mirror is wasted.