These kind of backup requires root/custom recovery
Root? Yes. For the wanam app. Or use adb shell & dd command.
Some ppl have partition corruption juz by doing ota updates, happened to me once. Its common. Ota don't require root.
Now I backup everything from 0-last KB of my phone, except system & data, the gzip it. Heck I can even restore the partitions to a second model and get the same s/no, imei, Mac address. This is not the qcn or baseband file, which is easily found for most models.
Everyone needs to do this backup, lose the phone serial no. Mac addr partitions, lose the phone soc board coz xiaomi service ctr can't do anything but change the whole soc.