I have this configuration and it does not work. I am able to make the firmware see the steppers (M122 report OK), however the motors don't actually move. There is no consistent documentation on the v3.1 chip. No one seems to know if you need to solder it into UART mode, nor do they know where to do that.
BTW: I don't think there is any support actually working this forum. Most post are un-answered.