I'm guessing it doesn't work on MIUI Premium either, but with the Uninstaller there to back you up at anytime - why not give it a try and tell us all if you're so into mods anyway?
I actually don't know how exactly the Uninstaller works. You should probably not consider my answer and wait for the OP to respond.
Have you tried flashing the 8.4.19 mod version?
8.4.19 weekly is a couple of hours away anyway and the mod is already there. Why not wait a little and flash a new weekly? (if the .19 mod doesn't work on the .12 weekly)