The method was insane, dangerous, and required EDL mode (Emergency Download Mode)—which Xiaomi had locked down tighter than a bank vault on newer devices. But for Snapdragon chips before the 8 Gen 2, there was a loophole: a signed firehose loader leaked from a forgotten factory repair tool.
When unofficial methods may be realistically possible
High probability of scams; requires giving remote access to your computer. Steps to Unlock (After Passing the Initial Check)
An active Mi Account (older than 30 days helps). The Process: Download the Xiaomi Community App from the Play Store. Set your region to Global . Go to Me > Unlock Bootloader .