I believe you can but you need another trailer kit that includes the relay and sensors. I really wish Ford would make it so you didn't need to buy another relay. Ideally they would have a relay in the rear bumper and you would just need to buy more sensors.
Over on the Tremor forums BroncOh has been selling some he created. I think he does them in batches and there is a wait list. https://subtle.design/products/tankwarden/ via https://www.fordtremor.com/threads/ford-diesel-locking-fuel-and-def-caps.5327/ (WARNING - very long thread)
BEM Auto has them for past years but still doesn't seem to have one on their website. You might try giving them a call. - https://www.bem-auto.com/
Yep. In previous years Ford would claim the 6.7 was optional on all trim levels which was not correct. Diesel was required on the Limited. (not optional).
How to lose customers ---> https://therecord.media/ford-patent-application-in-vehicle-listening-advertising
Who are the people that think customers want this garbage?
I hope that is driving around town aggressively. The computer in my 6.7 says I'm averaging 14.5 MPG pulling my 8K trailer @ 65 MPH. It averaged 23.6 MPG on the 1,500 mile trip home.
Ouch. Why a recall? Is this a common failure? Components and warranties are carefully created together. I've had a few vehicles with a sunroof and only use them a few times each year so I opted not to get one on my truck.
See if the dealer can cut the price some. Good luck.