I don't know if this is the kind of answer you are meaning, but I'll offer it anyway.
As a CSA It's my responsibility to sight the hand luggage. If it looks anything close to the maximum of 7kg then I weight it. Basically if they have lots of stuff to bring on carryon I will refuse them and tell them to check it in. We also have Security upstairs that weigh suspect bags as they go through Customs/ Immigration. If they are too heavy they are given a form to come back to check it in. I advise the pax that if it is too heavy it is a danger to everyone seated anywhere near them and that they could be sued for damages by another passenger and certainly they would be liable for medical expenses if they were hurt by overweight handluggage. At the departure gate the CSAs are also on the lookout for overweight/excess handluggage, so they have to make it through 3 steps.
Flown to 120 Airports in 44 Countries on 73 Operators. Visited 55 Countries and counting. Wanderlust is like Syphilis, once you have the itch it's too late for treatment.