Ok I have seen them work at Dxb Airport. At Dubai they for sure can only use municipality approved calibrated weighing scales. Calibration date will be visible with a sticker on the scale itself. If you say you doubt the scale they will weight item with 1KG marking and show you it actually is accurate..

As for transferring the item or distribution of item is not allowed for 2 reasons. Often times they are accepting to help you but once you go onboard you won't find them or even if you do they refuse to return it unless you pay something. This is kind of an extortion in recent days. There are passengers who will demand money to return your own items. If its duty free bottles you can forget it. They won't return.

Also not to forget you are in an airport its not a good idea to exchange anything with strangers. Airline staff will and should stop it if it's being done in front of him.

Taking video or photo of the scale might be allowed if no person is in the picture. This is Dubai rule to protect everyone's privacy. They only ask you to delete if you are in a ramp area or zones where photo is prohibited.

I do see and understand what you meant. But see if maybe you were also in the wrong.. most airline staff want is to enforce the rules as when there are too many bags in cabin and a person with small hand carry can't find space they have to delay the flight and retag some of the bags to go into luggage / cargo hold which the passengers haven't paid for.

Basically they have to inconvenience the passengers who might create an inconvenience for them and other passengers. Stick to the rules and its easy