Here is the scoop from AAA.
https://drivinglaws.aaa.com/tag/trailer-brakes/
My 2 cents by way of definition: Anything pulled behind a prime mover should be considered a "trailer" because it "trails" the lead vehicle. As such, anyone arguing semantics over TOAD versus trailer and deciding not to run a braking system on the trail vehicle is not someone I want to be in close proximity of on the road.
How much in a lawsuit can you afford to pay by not using a braking system if you should have an accident? If you're willing to take that risk, what's stopping you from cancelling your insurance and rolling those dice too?
Think about the potential consequences, folks....
GVP