Long time since I've had a G4 but maclyn actually made some real changes check it out here https://github.com/maclyn/QCView-G4 Quick Circle for AOSP based Roms by BigBoot modified to work on the G4 correctly.
I am not a developer, BigBoot made this possible and has even created an update that allows the y-axis to be offset specifically so we can use this on the G4 - all I've done is push a change with the correct y-axis offset for a G4 build.
Fixed issues
Locking/Unlocking sound when closing the cover - Issue fixed thanks to Codeworkx
Current known issues (CM13, other ROM's untested) -
No compatible call view, so there is no QCview for incoming calls. This is probably out of the scope of what I can achieve to be honest.