I have a 2020 Limited EcoDiesel with the 3.21 gearing and I love it. I use it mostly for commuting to work but otherwise connect my 23FB Airstream. The 23FB Airstream max's out at 6000lb loaded and with a bed load of other camping equipment, it tows just fine. I usually get between 17-18 mpg round trip while towing through the mountains of NH and into Maine. The big test is coming soon with a drive from NH to Myrtle Beach using the truckers highway to avoid most of the east coast cities. It's about 1100 miles each way with varying elevation so I'll get a better sense of mileage then.
To help minimize any sway, make sure you get a good weight distribution hitch and I recommend upgrading the rear sway bar to the Hellwig Sway bar.
Hellwig Sway Bar
Amazon says it doesn't fit the 2020 Ram but I confirmed with Hellwig that it does and I have it installed. I have it set on the middle holes and it helps greatly with towing and general riding, keeps the back end planted more firmly.
The only thing I'm really not happy with is the 22" wheels, they look great but they ride a bit harsh. I purchased a set of 20" takeoffs from a Laramie Sport with the Falken Wildpeaks and they ride very smooth and provide better grip into some of the gravel trails we have towed the trailer.
I'll be swapping out the 22's again for this next trip so I can have a smoother towing trip, I just wish I had the 20" rims from the Limited as they look much nicer.
I'm patiently waiting for Green Diesel Engineering to release the tune for the 5th Gen Ram 1500 and the 3rd Gen EcoDiesel. I used their tune on my old Jeep Grand Cherokee Summit EcoDiesel and it was a huge improvement over the stock tune. I'm hoping for great things when they release the tune for the new EcoDiesel.
Hope this helps.