My goodness, there are some stupendously incompetent cowboys about.
Yale’s top-end domestice rimlatch is the PBS. It’s British Standard rated. That’s not easy to achieve in a rimlatch. Yale have gone to a lot of trouble to make it strong and secure. And you will be paying a lot of money if you buy one.
All of the components contribute to its strength, it’s security and to its BS rating. Omit one of those components and the BS rating is invalidated.
I’ve just been to change a PBS-1’s cylinder. Whoever fitted the lock originally hadn’t bothered with the pesky bolts that secure the escutcheon to the door (the escutcheon is what surrounds the keyway); I guess it was too much effort to drill two more holes of just the right size hole in just the right place. They hadn’t bothered with the anti-drill spin plate covering the cylinder plug; I guess they dropped it and couldn’t be bothered looking for it. They hadn’t bothered with the hardened clip that prevents the cylinder retaining screws being attacked; “Duh. What’s this? Oh it comes off. Can’t see what that’s for. Bin it.”
So the customer had paid £100 for a lock (and goodness knows how much the “fitter” demanded) that was hardly any more secure than a £30 lock. And if a BS-rated rimlatch had been a requirement of their insurance policy, then their insurance company would easily have wriggled out of paying any break-in claim.