possibility to use ups hat?

Maybe it's a nice idea to add support for a usp hat, which safely shuts down the pi, when it's loosing Bluetooth/wifi on the phone? 
Or some other trigger. 

It will cost a bit more, but the SD card won't die in short and the power supply is stable at 5v.
Like this vor the PI Zero 2 W
https://www.waveshare.com/ups-hat-c.htm