Bangle 2. How to set GPS Serial1 baud rate?

This doc http://aitendo3.sakura.ne.jp/aitendo_dat­a/product_img/gps/HT2828Z3G5L/AT6558D.pd­f
tells that AT6558 uses automatic power mode:

AT6558 can provide two kinds of low power solution those are automatic low power mode and external control low power mode. Automatic low power consumption mode is that in the non continuous positioning scenarios, the chip positioning, internal procedures automatically turn off the power module, enter standby mode; Wake up automatically and carry on the next position by the timer. According to the different application scenarios, the program needs to customize.

I am not sure what "the program needs to customize." means.

There other ways, look at chapter 10.6 Low Power Setting