Vlad Safari still requires shift, but that is apple hasn't placed thought into accessibility for normal mice. But the behavior is that both vertical and horizontal scroll behaviors should be accepted. Currently Orion does not accept vertical scrolling behavior.
Normally on macOS, non-Apple mice simply scroll with alot of acceleration, that is the interval between each scroll is considered the amount of discrete inertia in which the scroll area moves, although there is no animation time making it very choppy.
Although I use a smooth scrolling application which intercepts all scroll areas and add it's own animation timer and scroll to the areas mentioned.
What should happen in both the Safari background options area and Orion is that vertical scroll inputs should be converted into horizontal ones. I am sure there is an API for that within cocoa UI.