yes, they do (redmi the same as other xiaomi phones) and that’s an important thing I left out.
I did create an account long ago with an alias email that i’ve used for the unlocking of several phones’ bootloader. it also requires a phone number for “verification” when you start the unlocking process, so for anonimity you’d need an unregistered burner phone number
so it does leave a trace in their books
the difference?