For anyone currently trying to install this, it does not work on Mimo version 4.86 and onwards. You need to downgrade Mimo to version 4.85 for pro to be enabled.
You can use Appstore++ by CokePokes to downgrade the app via the app store.
CydiaRepo for Appstore++: https://cokepokes.github.io
1. install cydia repo above and install appstore++ from cydia
2. go to app store, search mimo
3. hold finger on the open/install/update button
4. choose version 4.85 from the list.
5. wait for install and then Laxus' patch will work.
Many thanks to Laxus and CokePokes