Nope. The source code (someone's "badge library" on GitHub) has a few "issues" (bugs) reported.
And the code is downright scary ("let's try this, if we get an exception, then it failed, let's try the other way").
As with all undocumented features added by device manufactures (and that's what it is), it's easy to "kind of get it to work" --
-- but once this code is released for everyone, there may be issues, crashes, including crashes of the phone's home screen, wrong counts displayed, effects on other apps, etc.
And so, bottom line, if Xiaomi wants to make this an official documented version, then we'll consider it. Until then, sorry, no.