I would love to be able to map the thumb buttons below the horizontal scroll wheel on my MX Master 3 to move between open tabs in Edge. This would be especially useful given I can orient my tabs vertically along the left side of my browser window; the button that default to 'forward' in the browser history would move up this vertical list, and the button that defaults to 'back' would move down this vertical list. Using an app-specific gesture to move through either tabs or browser history could also be a useful customization.