Oh that’s what I had to do for my Mi 11x/F3 as well. Good to hear. I remember reading that Xiaomi had gone the way of Samsung and completely stopped official unlocks.
I believe the reason they do this is because some resellers were unlocking the bootloader and installing a ROM with malware and selling that off to unsuspecting customers. This delay (and needing to be registered with a phone number) makes that process both impractical and easy to detect.