I don’t believe there is currently a way to detect when a player clicks in the scroll wheel or not but if there is a way please do inform me.
Although the applications may be limited, many games could possibly take advantage of a player clicking the mouse’s scroll wheel. Shooter games would have one less key on the keyboard that is awkward for the player to use, building games would be made simpler with more options for the mouse, fighting games could be improved by using the scroll wheel as a lung instead of a double-click, etc. The applications may be limited but there’s potential. It also just makes sense that this exists as there are WheelForward and WheelBackward events. The only issue that I could think of is that people with trackpads, touch devices or only two buttons on the mouse won’t have this available.
Edit: I found out MouseButton3 was a UserInputType but I still believe that it should be simpler to use as just an event much like mouse.Button1/2Down/Up