One of the reasons I started using Opera years ago was I liked its mouse gestures. I think it is one of Opera's best features. But, when viewing a 3D object, some viewers like MakerBot Print Online, Onshape, IceSL, Thingiverse Thingview requires right click to be pressed and hold for rotating or panning operations. I don't know if you can detect WebGL using right click for those and disable the mouse gestures for that right click, so I would kindly ask if you can make an option for turning off the mouse gestures for certain domains. For example, if you would like to add Onshape.com domain to that list, you would select it in the settings under mouse gestures settings.