In Watch Management under 'Watch Settings', you find the option to switch on the 'Confirm safety on movement (inactivity sensor)' feature. The inactivity sensor is working together with the safety timer. 

When the safety timer and inactivity sensor are active, safety is automatically confirmed when the wearer moves their wrist.

This avoids the need to press the screen to confirm safety. The inactivity sensor is only activate after 80% of the timer interval has elapsed.