Sorry, I must be very confusing
You were right. The only reason I tried taking the GPU out was to figure out what's causing the problem to get more information for you.
I decided to restart from step one again as I was unable to update High Sierra to 10.13.4.
What was happening was, I would download the file no problems, click install, it restarts, but still showing 10.13.3. So I thought hey, I'll create the boot file from 10.13.4. Now the USB shows in BIOS, but doesn't appear in clover. I stupidly erased my hard drive to do a clean install as well.
I've checked
https://www.tonymacx86.com/threads/install-option-not-showing-on-clover.239526/ &
https://www.tonymacx86.com/threads/install-option-not-showing-on-clover.239526/; I checked for apfs.efi, file is there. Hasn't really been a solution to this install not appearing issue.
I tried buying a new USB as well, thinking maybe something was wrong with mine. Still same issue
My BIOS is the same(for using igpu to bridge to GPU later), pictures attached. And also the CBM without install macos