I enjoy reading posts by someone who knows what they are talking about. Good luck with your new equipment.
In this area, I believe the DOT concentrates its efforts on those they believe to have flagrant violations. I drove route trucks, straight trucks licensed up to 48,000 lbs, for 30 years, and was never once pulled over by the DOT. In fact, I have been waved through a checkpoint a couple of times without them checking anything.
As for guys in the biz, I've never heard of, or seen, anyone transporting mowers being pulled over and checked. I see vehicles pulled over on a regular basis, but they are generally semi's, some kind of junky looking rig, or trucks hauling rock or gravel.
Dependable Mowing Service