With the advent of decent battery operated tools these days and ultra thin cutting discs a lot of us need to rethink our security . New tools are quiet and quick and even cheapo bolt cutters will do most chain unless it is hardened. Reasonable quality tools have come down significantly and even cobaltt drills etc are so much more affordale
Sometimes bulk and a muck metal, or cast surrounding a hardened core may be bulky on a trailer hitch but will take them extra time.
Gotta think like a thief and recent ones I have hear of they bypass the security devices with ratchet spanners to remove wheel nuts and wheel lock, straps to tow without removing trailer hitch ( they don't care about tow cars bumper as it is also stolen)
Opportunity for better design or update to hitch locks to stop acces to small angle grinder blades or dremens with carbide burrs .
Won't be long before there is small battery welder you will blow through most metal security aids in seconds so maybe composites will be required