If you wanted to keep the bike as stock as possible, and it had a few problems, there is a lot of status information you can get from reading the status screen of the MBB, and this can help in troubleshooting the bike.
For example, the battery pack sends its status over a canbus network to the MBB, and you can see all the cells voltage as well as the total voltage from the status menu of the MBB. The MBB uses this to make sure the battery is ok before and while riding, and to inform the dash battery meter. Also, the MBB manages a lot of safety features, for the rider as well as the bike itself : current reading from the battery pack, current reading to the motor, temperature reading of the motor, starting the fan when required, precharging the controller capacitors for a few seconds before activating the main contactor so it doesn't arc and wear it... Also, there is a bunch of calibration that can be adjusted to modify how the throttle reacts, acceleration limits, current limits...
Going your way and just replacing everything is another way to go about it. A lot easier too.