The BL unlock restrictions aren't as much stringent on Global rom as those on Chinese rom, the only prerequisite for BL unlocking on Global rom is that the Xiaomi community app version must be 5.3.31 or higher
Even reaching Level 5 isn't required on Global Xiaomi community
According to this Chinese questionnaire on GitHub, (you can freely translate it to English or any language you want via Google Translate)
小米 BootLoader《解锁资格答题测试》更新记录. Contribute to MlgmXyysd/Xiaomi-BootLoader-Questionnaire development by creating an account on GitHub.
github.com