Here's my experience with adding a DC to DC converter. 2016 Ford and Lance camper with all the wiring per their recommendations. While I got some charging out of the truck it was less than optimal and trying to run the refrigerator on DC meant I got to my destination with low batteries. The longer I drove the lower the batteries got. It just didn't work. I also got tired of messing with running the refrigerator on propane. Sometimes it worked fine and other times I arrived with it out...added baffle....new thermocouple... etc. Based on recommendations from a lot of people I decided to add a DC to DC converter.
Bottom line. The DC to DC converter just works and works well so I arrive at my destination with fully charged batteries and a cold refrigerator every time. I went with the combo Renogy MPPT and DC to DC all in one (DCC50S) to replace my PWM solar controller while I was at it. It gives 25 amps from solar and 25 amps from the truck with priority from solar. It will also charge the truck battery from solar if it gets low when you are parked for a long time. For me it was the right option and I should have added one a long time ago. It is also LiFePO4 compatible so when I upgrade batteries I only need to change the setting. If your rig charges while driving, or you don't need it to, then a DC to DC charger is not for you. For the rest of us.... they are awesome.