Should I use cruise control while towing a travel trailer

It's OK to use cruise control as long as your transmission has a manual option and you can control which gear you're in. We have a 2013 Explorer with a 3.6 L V6 and a 6-speed A/T towing a 5000lb Lance. The problem with the A/T is that it tries to keep the rig close to the set point which involves shifting down on the slightest up-hill and shifting down to much lower gears than is necessary. By using manual shift I can keep the cruise control happy most of the time even though the speed drops by 10 mph (or before the cruise control quits). On average I'm in a much higher gear than the cruise control would pick and this lowers the fuel consumption significantly. The downside is that my average speed is lower and I have to listen to the engine or look at the speedometer frequently - but this keeps me alert. As an example, on a level highway I can travel at about 53 mph in 6th gear with the cruise set at 60. In A/T I'd be going 60 mph in 4th gear.