I implemented a simpler version using Tasker. Previously, the battery full notification didn't bother me as I had a Tasker night profile on that silenced the phone when on charge during the night, but I recently bought the Power Pack charge case which kept causing the phone to notify me that it's fully charged and turning on the screen in the process (and running down the battery that it's meant to conserve, in the process).
To fix this I did the following:-
1. Using a rooted phone, rename the OGG file for the notification sound:-
Using Root Browser app, I navigated to system\media\audio\ui and renamed the tw_battery_caution.ogg file to tw_battery_caution.bak
2. Setup a Tasker profile called "Unlocked", that upon the Display Unlocked event will set the custom variable %Unlocked to "1".
3. Setup a Tasker profile called "Locked", that upon Display Off event will set the custom variable %Unlocked to "0".
4. Setup a Tasker profile called "Battery Full", that upon Battery Full event will activate the System Lock action. It'll prompt you to allow Tasker to be a device administrator when the System Lock action is added. System Lock basically will turn the screen off. An "if" condition is added for the action that checks that %Unlocked is "0" before carrying out System Lock, otherwise the screen will turn off when you're using the phone.
This seems to work for me, and also enables my Power Pack to report fully charged status (blue LED). Previously, when the screen was activating it would never report itself as fully charged, so I guess the notification was draining the battery (ironically).