If at one point you are considering a batterey back up Xiaomi repeater, take a look at my project.
It is a environment sensor (temperature, humidity, pressure and light) with a twist. It is DC powered so it can be a repeater to Xiaomi devices. It is battery backed up so that in the case of power failure the Xiaomi devices have much better chance staying with the repeater rather than looking for a new parent wihch may not be compatible. I forget to mentioned that the Zigbee Radio has extended range amplifier.
Thanks
Iman
