In the BTT configuration window, what does the ‘Reset’ button next to the ‘Save’ button in the far right action-editing column do?

Out of curiosity, in the BTT configuration window, what does the ‘Reset’ button (circled in green in the screenshot) next to the ‘Save’ button in the far right action editing column do? as when I click it nothing actually changes to the action or trigger, and the button is always greyed out. Thanks!