With a scroll-wheel equipped mouse connected, Firefox on Mac has the shortcut of zooming a webpage in and out when the user holds down the command key and uses the wheel to scroll up (zooms in) and down (zooms out).
This is mapped according to the "Scroll direction: Natural" setting in System Preferences - whichever scroll wheel direction scrolls up also zooms in, and vice versa.
Please implement this shortcut on Orion too.