My own issue with these 'checks' when they happen is that the majority of the weight in my hand luggage is from electronics that couldn't be checked in regardless. This is why it's ridiculous to insist on weighing the laptop bag, you aren't allowed to check it in. You can't check power banks, you can't check camera batteries, etc. I've never flown QR in economy so have been given a pass even though my backpack nearly always exceeds 7kg.

Interesting that the OP mentioned they were threatening penalties at the gate if you didn't have the sticker. How about people transiting from AA or AS and not using the LAX check in counter? When I've transited from AA at DFW they didn't put the silly sticker on my backpack but did insist on printing their own boarding pass at the gate vs using the perfectly good one that AA issued me.

I have quite a lot of QR flights this coming year. I'll have to remember to keep my pocket vest handy just in case some overzealous agent decides to weigh my very heavy gaming laptop. Aye Gear Vest I haven't had to use it yet and it itself is pretty heavy with all the zippers but I'm fully prepared to deploy it and put all of my cameras, chargers, power banks, etc. into it and wear it anywhere a scale for hand carry is in use.