I can’t speak for EK, but travelling F or C with several other airlines, I’ve never had a problem with slightly oversized or overweight cabin bags.
Recently flying Swiss ex MXP in Y I was asked to weigh my bag and it was 12kgs instead of 8. I said I had a meeting in the airport and was handing over documents to my colleagues which would reduce the weight to 8 kgs. She replied I had to come back to the counter to reweigh and get the cabin baggage label. I headed direct to the lounge and boarded without a problem!