I saw that some people rebind F11 to a mouse button in order to make using it for lag easier, but I'm having trouble figuring out how to do so. I don't see a line for it in the .ini files. Am I looking in the wrong place?

F11 isn't a binding in the game, it's an OS binding - you have to use first-party mouse software (Corsair, Logitech, etc.) to hardware change your bindings. Things like AHK (rebinding in software) are disallowed. You can also only rebind one button to one button (i.e. F11 to a mouse button, or Alt to one mouse button and Tab to another, but not Alt-Tab macro to a single mouse button).