Unlock bootloader without wipe. Does it still work?

[diabolicgod]

Hi.

I have a Xiaomi Mi A1, on android 9, with android security patch level 2020-03-01; and I need to unlock its bootloader and root it, without wiping it. Its critical that I unlock the bootloader without wiping it.
My question here is, does the "volume down" trick still works on this latest updates, or was it patched already?

Thanks for the help.

Dia.