if you have a Laptop must work, but I doubt if you are using an external monitor, their EDID are published by their EEPROM, so, attention if your Display product/vendor ID already exists in your Overrides folder.
the customedid key for me don't work, clover loads the key, but result in nothing if don't apply the fix in file
i don't have graphics at all, only black screen.
ProductID-717 indicate a generic files generated by Osx visible in ioreg (not a real product ID), and video acceleration is really required for override the EDID, your display must be attached to the framebuffer, without, injection does not work!
search mmod, for real Product/Vendor ID