Select everything to make full backup and keep it on external storage.
the rom in question is the Kang, I made a backup of all the items, I started the restore after a few seconds a message comes out: extractTarFork () process ended with ERROR: 255
Set Phone as default.
You can easily go back to xiaomi.eu. I jump from it to custom roms and back without any problems. Just make full backup with TWRP. Additionally make backup of persist.img just in a case. If it's destroyed you will loose L1. So, it's good to have copy of the image. You can also easily move all your apps, contacts and messages with Migrate. I use it all the time and I can recomend it.It is nice to read the positive reviews about this ROM.. also about the camera, which is very important to me too.
So I haven't tried a non-MIUI Rom on my Mi9 yet.. lately relying on xiaomi.eu - and the beta ROMs are great.
What I want to ask, should I try this ROM out, what is the case going back to MIUI ROMs with regards to Widevine? Is L1 lost?
And anything else I need to consider that is irreversible after making the jump to AOSP?