Quick tl;dr note: unlike most other software that let you do this (USB Overdrive, etc.), SensibleSideButtons binds your side buttons to fake three-finger swipe gestures instead of Cmd+[/Cmd+] shortcuts. This tends to work far more reliably across the OS, and among other things, works natively in Xcode instead of indenting the current line. I noticed the Logitech MX Master doing this with its side buttons so I thought I'd port this behavior to all my other mice too.