not rated doesn't really mean anything in the states, except if you are a truck enthusiast and want to feel "superior" while driving a horribly inefficient brick everywhere "just in case". But for efficiencies sake (and cost) a trailer is absolutely the best way to go in %99.999 of cases.
And I don't understand your logic, if you wish to imply that the leaf driveline is not suitable for towing (even though there is no evidence of that), how is putting it in a different body going to help?
I don't know what you are asking for since it sounds subjective and not evidence based.
I mean it is fine if you like trucks, but don't be throwing shade on trailers, because it really is just bs.