Keep in mind that some states require brakes on trailers based on UNLADEN weight (often 1000 or 1500 lbs), and some require brakes based on GVWR (often 3000 lbs or more). Reciprocity usually does not apply to braking requirements.
IMO, most "ratings" are based on lawyer input, often due to stories like the one about the person who set the cruise control, then went back to get a cup of coffee. After the accident, a lawsuit was filed because the Owners Manual did not state that the cruise control was not an auto-pilot! Fake story? Probably. However, lawyers think like that!
As previously stated, the best bet would likely be to get the trailer fitted with surge brakes. That would solve the problem!