Hi, I'm trying to follow your steps, but I have problems with the step 3.
To push the Xioami.eu rom inside the internal storage I run through adb: adb push ROM.zip /sdcard/
C:\Flash>adb push xiaomi.eu_multi_HMK40_POCOF3_V12.5.3.0.RKHCNXM_v12-11.zip /sdcard/
adb: error: failed to copy...