I am a bit surprised at the 12.4 towing, I towed my Aliner camper, 2500 pounds or so, similar shape, 8000 miles last summer at 60-65 mph getting 16-17mpg. I wonder if they are pulling at 70-75 where the truck is constantly shifted down to 6th or 7th gear. I picked my MPH based on my RPMs, goal was to stay right at 2k most of the time. This was a Wrangler with the 2.0 Turbo but same / similar results in the JT I purchased after this road trip, on shorter trips.
I test drove at 2021 Tacoma pulling my Aliner and the 22 JT I bought and noticed at the exact same spots on the hwy at the same speed (65 mph) the Taco was at 2500+ rpm vs the 2000 of the JT, not sure if that was torque, 8 spd vs 6spd or combo. But it was the deciding factor on buying the JT vs Taco.
The killer app will be if the hybrid somehow brings this up / if I could get 20-22 mpg TOWING at 65 mph that would be a game changer. I seriously considered JT diesel for that reason but the fuel pump issues scared me off.