I look at this a little differently.
If you are exceeding ANY of the maximum values on the unit (RV, hitch, tow bar, etc) you are setting yourself up for a major problem.
Should you have an accident and the police, insurance company, other driver, etc. find out I would not want to be in your shoes.
Insurance company will look for any way to decline coverage.
If they decline coverage, do you have enough cash to pay the other party?
Stuff happens, your fault or not.
DON'T put yourself in that situation. End of story.