What’s the big deal with locking gas caps? Do people actually steal gas at alarming rate that these are critical to have?
For sure with the tether only being 3" there is no way to do as I did in regard to a hook. By the way the tether on my JKL is 6" in length.
I think if I were in your situation, I would ask the dealership parts guy to obtain a replacement fuel cap for a 2018/2019 JL. Once he gets that unit in, see how long the tether is on it. IF, it is 6" in length, then go to the Service Department, Manager, and ask if he can have your fuel cap replaced under warranty. You might just fund he will do this.. if you approach him in the right way, lets say. If he won't ak him to sell you at dealership cost which is probably about $12+-.
Yes, I think there is a very good chance the replacement fuel cap that the parts guy gets will have a longer tether. If not the parts guy will keep in their stock or return it to their centralized parts center.