There is no need to delete any handlers. Please do NOT exclude your lock or you will need to have the script run again.
Running the script with either the stock device handler or the Universal Enhanced Z-Wave lock device handler installed is okay. In either case the notifications will start working after the script has been run successfully.
It’s okay to switch device handlers manually from the IDE after the script is run but do NOT exclude the lock after the script has been run otherwise you will lose the notifications and the script will need to run again.