We have the right to ask for our data (¿¿Remember GDPR??), so you don't need to do techie things or any hacks to get your data, it's as easy as ask for it to xioami: email@example.com.
Or without email:
You can export your data by signing into mifit.huami.com/t/account_
It will download your data in CSV format!
This works for huami articles like (Mi band) you may have to read about privacy for other xiaomi products.