I did quite some progress into getting this board to work with PlatformIO low power mode.
The last thing I need to figure out is how to disable the blinking blue LED when advertising.
@jonyu I doubt you can go lower than what you can achieve with nrf52840 and the same level of support of Nordic, have you considered creating a shield with just the MPU?
Example: MPU6050 super thin feather from Turing Complete on Tindie