I'll second that! Get one of the RV units. Both RM and Garmin work great and many come with free lifetime map updates. (Ford charged $150.00 for a recent map update, not sure about GM or Ram.)
Our F250 came with the OEM navigation system, most of the time we use both when towing. The Rand McNally "Don" and Ford nav system "Hillary" both have their good features, but whenever there is a conflict, we defer to Don
and mute Hillary!
Maybe one day Ford or GM or Ram will wake up and equip their "built for towing" vehicles nav systems with the ability to enter parameters for trailers.
Mack & Mary Ellen
2016 Cedar Creek 36CKTS, 2019 F350 DRW
When all else fails, read the instructions!