Hello, it finally worked :DD
The second BIOS chip which I located under the heatsink was just a vBIOS chip, it contained only 2MB of data which was all describing the Nvidia GPU. So I went back to the first BIOS chip and kept modifiying the original file.
Previously, I was editing the CpuSetup instances found only inside of EfiSystemNvData, but turns out there are 3 instances of CpuSetup inside the padding area above EfiSystemNvData and 1 instance of CpuSetup inside the padding area below EfiSystemNvData
After modifying the padding areas’ CpuSetup along with the EfiSystemNvData’s I flashed the “modded” BIOS again and upon reboot the variables were finally changed.
I changed CFG Lock, Overclocking Lock, Undervolt Protection, Overclocking Feature, and FLL Overclocking Mode Enable. I confirmed that the changes were applied and active using RU.efi.
So I was finally able to use Throttlestop and XTU both of them became unlocked and fully functional.
Seriously much much thanks to you @Sweet_Kitten!!! Especially for informing me about that Github issue of UEFI-Editor and directly editing the NVRAM variables.