Frontal area resistance when towing the Trillium Outback with the Wrangler won't be an issue. The manufacturer will say that "exceeding these limitations may significantly reduce the performance of your towing vehicle", and that's true.
... but, I had a very similar setup to yours when towing my Trillium 4500 (actually larger than your Trillium Outback) with a 2011 Ford
Escape with 3500 lb towing package. With my setup, I easily towed over 15,000 miles, over mountains, with strong headwinds, and other adverse conditions. And the 2011 Ford
Escape had the same towing limitation (32 sq. ft.).