I bought the 4/64 blue variant yesterday and today did these steps:
! Warning. All data will be permanently erased, those steps are for a phone that was bought as a used one and I don't care about the data of the previous owner but if you are updating your private phone backup everything before!
1. Downloaded the latest official Android from Xiaomi as the phone was still on Android 9 and the automatic update said that there are no updates.
Go to https://xiaomifirmwareupdater.com/miui/daisy/stable/V126.96.36.199.QDLMIXM/
and download fastboot .tar format, unpack it with 7-Zip so you have a folder with .bat and .sh files inside.
2. Downloaded MiFlash20200314, now I found the newest here https://androidmtk.com/download-xiaomi-mi-flash-tool
but with 20200314 all went well.
3. Done bootloader unlock https://en.gizchina.it/2018/10/xiaomi-mi-a2-lite-bootloader-twrp-root-magisk/
4. Using MiFlash I have flashed V188.8.131.52.QDLMIXM, select "Clean All" in right down corner otherwise bootloader will be locked. It will take up to 10 minutes be patient.
5. Installed TWRP https://forum.xda-developers.com/t/official-recovery-twrp-for-daisy.3855396/
6. Copy Arrow-v12.1-daisy-OFFICIAL-20221117-GAPPS.zip to SDcard
7. Reboot to TWRP with power + volume up. Then Wipe -> format data -> choose install, choose zip and wait.
8. First boot will take about 3 minutes if it takes significantly longer time something went wrong. You can always restart the process from step 4.
Currently, that phone can be bought very cheap about ~USD 60-70 (in Poland) from second hand in perfect condition and with Android 12 it is a great phone for basic usage. Still, there are batteries and other serviceable parts available, like button switches which fail after about 4 years. It is easy to open back (many tutorials on youtube) and replace by yourself those parts.