Do some machines remain bricked even after flashing stock BIOS?

I’m concerned with programming the SPI chip of my Lenovo Ideapad 500-14ISK after reading this post.

The procedure I’m attempting to do is simple: read the flash chip, compare the dump with the contents of the chip, and store it in a safe read-only place. Open the image with UEFI Tool just to check if it is indeed an Intel image with the ME, BIOS region, and not some random data. Then make a copy of the original dump with a distinctive name into a separate folder and make the necessary modifications. Flash the modded image using the programmer, clear NVRAM by removing the CMOS battery, and boot up the machine. If it fails to boot, flash the original dump, clear NVRAM, and boot again.

Given that I would be making modifications to the ME region, I’d like to know what modifications could render the machine irrecoverable to a functional state, even after flashing the stock image dumped using the programmer.

I’d also like to know if there are indeed machines with flashing protection mechanisms that would render the machine inoperable or irrecoverable after flashing the firmware chip, even with the stock firmware. I read something about Secure Flash but afaik it is only triggered by a mismatch of the BIOS image checksum, so my guess is that flashing the OG dump won’t trigger the error again.

I understand that physically dumping the flash chip has its risks, like for example applying the wrong voltage and burning the chip and maybe some other components. But other than that, what things should I take into consideration to preserve the machine?