How strict is Jet2 on their cabin bag dimensions?

Guidelines say 56x45x25, I’ve got a duffel that at max stretch seems to be more 57x35x26, which I think will be fine since it’s a bag that I’m able to squish down and it won’t be properly full when I go, but the friends I’m going with are worried that my bags going to be charged or left behind at the airport. I think that in theory tired airport workers aren’t getting paid to care about luggage sizes any more than “if it fits in the box then it’s fine” but if anyone’s got personal experience it’d be appreciated.