I am very satisfied with xiaomi.eu-roms. I´ve used them always with my Mi 5S before and now with the Mix 3. I noticed some problems with my Mi Mix, also in the last versions:
When my Mi Mix 3 is in the pocket, it seems, that it activates itself many times. Opening the app menu, there are often some apps in the background, i didn´t start before. Without lockscreen security, but also when i activate the fingerprint security. Don´t know, how it happens, when the device should be secure. Isn´t there a pocket mode as in other phones, that stops activities by the proximity sensor?
In the new version i like to have the percents shown for battery. I think, it would be good, to have it as the only one, because with this feature the symbol is unnecessary.
For the TWRP problem i used the batch file from trading shenzen, then it asks not for a password.
With poco launcher the MiUi is mostly pefect for me because of the app menu in it. But i think it´s time to have an ability for partitions in the bigger space of new phones. So it´s not necessary to copy documents, music and pictures to the storage again, if you make a factory reset/ format data for a clean install. This would be a good idea, using our phones more comfortably. Also it would minimize the data volume for backups.