You're right, most states incorporated the DOT published rules by reference into law. States can definitely tighten the DOT rules by state law but they can't make them looser. I'll bet most officers don't even know about the interpretation but a judge could certainly determine it's applicability. To prove some of your status would take significant documentation that you definitely wouldn't have with you on the road.

Definitely the bad thing is it's getting worse and worse and we definitely won't hear the end of it.