If you are riding with your hands in that far for comfort, I would cut them. I would recommend verifying that it is a comfort thing and not because your grips and controls just happen to land you there. You can experiment with some soft foam grips, you can slide them around pretty easy with some alcohol. You can also cut them to just barely fit your hand and place them in different locations, adjust your brake levers to match the positions, and see what is comfortable for you. Cut to match.
I had 680 on my old XC bike, it was totally acceptable. I ran 720 on another bike and felt it would have been better and considered changing my XC bike to 720. My current XC bike came with 740 and while the control is nice, it feels too wide for bar bashing in a mass start. But they bike is so well built components wise I don’t want to waste my money changing anything.
My trail bike? 800mm. I would consider experimenting with 820 and a slightly shorter stem (came with a 45mm). But the 800 is comfortable and works, so I am not in a rush to change it. And yes, my hands are on the very far edge of the grip.