Is there a way to have presets for the On The Fly Sensitivity so I can swap between 2.5 at 6.5 with the press of a button?
In a word, no. I'm totally out of touch with games nowadays, but back in the day I used to bind all of these adjustments to game commands and then assign them to a mouse button. For example, in Quake you had the "sensitivity" command and, with a bit of scripting, you could make a key/mouse bind toggle between two preset levels. Is this possible now?