5 years ago I travelled with El Al and I had 6 kg over – I had 26 kg where 20 is allowed (flights inside Europe and from Europe to Israel allow only 20 kg, unlike flights to the US which are usually double that).
I was so scared I would get a huge ‘fine’ for this (it could have been +1000 NIS easily)… Then I got to check-in, got boarding pass, handed over luggage, and … “have a nice flight”?! I just walked off when I thought, “huh?! wasn’t I supposed to pay for that?!” – so I actually walked back and asked about it. I was told it was ok!
+1 for El Al.