Both Clover_r5119 and r5120 have OC options, but they are not required for the system to boot.
Best way to test either version is to get hold of a spare USB pen drive, install the version of Clover you selected on to the pen drive, using the same options you selected when installing Clover to your macOS drive.
Then you can use the Bios Boot Menu to boot from the pen drive, while leaving your current setup in place.
You will need to use the ClearNvram option in Clover, F11 key needs to be pressed while you are on the Clover boot screen. Then reboot the system, if it doesn't do it automatically.
Then when you next boot from the USB pen drive you should be using the Nvram settings from your pen drive config.plist, not the settings from your macOS drive.
I would suggest you use a different Clover Theme on the setup on the pen drive, so you know for sure that you are not booting from your macOS drive. There should also be a record of the version of Clover you are booting in the bottom right hand corner of the display, when you are on the Clover boot screen.
Example of Clover boot screen with version in bottom RH corner
This theme is called Catalina and is one I used on my systems when I was booting with Clover. I have attached a copy for you to use, if you want to on the pen drive Clover setup.