No idea about that Bafang, but it could be as simple as some bikes just don't have a throttle installed, but the plug is there. On the original Sondors, they had a jumper plug for the LCD lead in the controller. If you added an aftermarket LCD, you removed the plug and then plugged in the display. Now they use a proprietary language, so you have to use a Sondors LCD to be compatible. Same could happen with throttles for other manufacturers.