Can't see USB drive

[agon04]

I've got a MacPro5,1 with Nvidia GT730 GPU - i.e. no Boot Screen.
I am not able to boot from USB or Hard Drive - can only boot using Clover-5163-X64.iso while pressing "C" button after power-on.

My issue is that Clover Boot selection does not show the USB stick containing High Sierra installer.
Please note that if I boot this .iso in VMWare (i.e. UEFI mode as opposed to BIOS) the USB can be seen and when selected boots into the Installer.

Could you please advise if this can be resolved by a different \EFI\CLOVER\config.plist ?
And if "yes" how can I rebuild the .iso ?

[SergeySlice]

If you apply preboot.log then I can see what is happen.

[agon04]

I am booting from the CD-ROM and there appears to be no options to write anything other than to "/EFI/CLOVER" folder (which is read-only):

[SergeySlice]

Yes, you can't save to CD so you should boot from USB stick.
I see no why it is impossible.

[agon04]

Do you have instructions on how to create Bootable USB from Clover-5163-X64.iso.7z ?