Use Config.plist from the bootpack. Your issue was that you're missing HFSPlus.efi which is included in the EFI_4184
Note: Bootpack (EFI) consists of combining the Generic EFI + the model you're downloading!!!
If you don't want to use the Generic EFI, you could mod the Config file, under Disable Drivers, remove VBoxHFS, that should fix issue you're having.