Your mobo isn't UEFI, is normal Bios...
Boot with 1 while cursor is blinking for Change bootloader... change for Chameleon.
boot with: -v cpus=1
Note: You have InsydeBios, so you need everytime boot with cpus=1, no problems about this, in future won't be necessary boot with this anynore
Your bios is very limited, so do what i said... try remove all Nvidia kexts to force use Intel graphic.
Remembering what you said earlier about Mac working in Legacy as well as UEFI, i tried booting in Legacy boot mode instead...
When booting in UEFI, Clover appeared instantly and there was no blinking cursor like you described. It was impossible to press the number 1 because there simply wasn't enough time between the BIOS disappearing and Clover coming up.
But when booting in Legacy, the cursor appeared straight after the BIOS screen and i was able to get into Chameleon by pressing 1.
I typed the boot flag that you suggested and pressed enter, and amazingly it worked! After a lot of scrolling text it finally reached the Mac installer, much to my relief!
I have tried iATKOS ML2, and iATKOS ML3U (Which took 6 hours to download each), but this genuine version of Mac is the only one that has worked. If it wasn't for you i would be completely stuck, so thank you.
I really appreciate the help you have given me today. It has taken about three weeks for me to get to this stage, so you can imagine how pleased i am.
Thank you once again.