Locking a Treg Hitch?

With the new trailer having a versatile Treg Hitch I’d be keen to see how people secure their trailers to prevent theft. What’s best for the tree hitch, or do you just put a D-lock through one of the wheels. How do you prevent a determined thief with a power tool?Alternatively GPS trackers look pretty good as a second line of protection. What are the best models out there?