It’s does a ton more stuff like proper gps and maps onboard, custom modes - you can use the normal 4 riding modes and program your own version of the 4 modes with different response curves, range that takes terrain into account in guidance modes etc etc. Loads of info on YouTube!
Not sure to be honest. I watched my lbs do it and they just connected the plug to where the Purion plug went (just above the motor) and positioned the cradle on the handlebar. They charged me £25 to do it all, took 20 mins.