Arching may be beneficial depending on your goals, but make sure that the majority of your arch originates from your mid and upper back and not your lower back. If your lower back cramps as you prepare to lift, you’re out of position and putting yourself in danger of injury.
The arch position can be tricky to get used to if you’ve only performed traditional bench presses before trying the board press out. Work with your spotter and be honest with your body as you prepare.