1) Not too sure whether the schematic is up to date. I could see "Bluetooth Module(Not used)" stated in the schematic while the board clearly shows the BLE module is attached to the multimeter. BLE112 (Bluetooth v4.0) is actually reaching its end of life (https://www.silabs.com/wireless/bluetooth/bluegiga-low-energy-legacy-modules/device.ble112) so the multimeter (or its subsequent units) maybe using a newer bluetooth module
2) Multimeter with Bluetooth is not yet a common feature available in the market (with some brands opt for other sort of cabled or wireless communications) but definitely a great addition to extract the data from the multimeter to smartphones or laptops.
3) The meter itself is powered by 4xAA batteries whereby most of the multimeters are powered by 9V battery. It maybe the case that such configuration may allow it to last up to 500 hours (Fluke 87V which is one of the multimeter with long lasting battery life is rated only at 400 hours and it is using 9V battery).
