My Mobo is an ASUS Maximus IX Hero with Z270 chipset, so is a 200 series one. Tried almost the same things as in your EFI (same kexts in Clover, same UEFI64 efi drivers, same other clover parameters), and still the same issue, it just restarts after attempting to load the graphic driver. Something is very wrong with this driver, as installing a vanilla HS is a breeze with no issues in my machine (I have installed it 6 times now, no issues to reach installer or anything). Just the Nvidia web driver break things apart badly and PC is not able to boot macOS at all. Really some fix should be released by Nvidia as I´m reading this is also happening on Mac Pros with GTX cards.