Hello,
Greetings!
Actually, We integrate and test only Mi band 2 with our devices, Which provides you with the heart rate of the watch holder.
We didn't test Mi band 3 yet, It is good to hear that it is working with our devices,
I would to highlight this point: as long as later versions of Xiaomi Mi Band use the same BLE protocol as Xiaomi Mi Band 2, there should be any issues
Thanks!