I repeat, 5th wheel hitch thefts have to be planned, not "Ooh, that one looks nice, let's take that one". That means they come prepared to take the hitch. Those locks on Cummins12V98 will probably take less than a minute to defeat, all 5 of them.
I don't mean to be such a downer, but let's be realistic about it. 5th wheel hitch theft has to be low return for the amount of effort involved, so they aren't going to be casual lift-and-run thieves.
I'll leave mine unlocked, unchained, and covered by my insurance. :)