Don't know about your F350, but my Chevy, brand new, recommended no towing for the first 500 miles.... Oops! After I towed (almost from the first day, to the first 1000 miles) I eventually found that warning in the owners manual. Well ... she's still running just fine after 3 years.
Something to look into, what do they recommend for initial break-in and towing?
Also, when you get it, check your DEF and make sure the tank is full. When we got ours, I had to fill my tank after less than 1000 miles the first time. Talking to (a different dealer, because we were on the road with the camper, when the warning went off), he thought the tank was not full when I took possession of the truck. Probably had just enough in it to get it out of the factory. DUH!
Live and learn. Intervals between DEF fill up did get longer and longer. No problem now!