As a user who makes frequent use of MMB (Middle Mouse Button), Ctrl+MMB, and Shift+MMB for Pan, Orbit and Zoom, I would appreciate having an additional, option mappable to Alt+MMB, in the Application Options menu Display tab.
The proposed fourth option, to go with this fourth available key+mouse button combination, would be rotation in the plane of the screen (ROTATE within the graphics window), equivalent to holding F4 and dragging the left mouse button just outside of the large circular reticule that appears.
The benefit would be additional configurability and convenience to users who prefer to navigate using the bottom-left area of the keyboard, not needing to reach up to F4 and switch between middle and left button. View rotation in the plane of the window is sometimes useful, indeed already existing in Inventor.
Equivalent functionality exists within some rival CAD systems.
