CPU-Z gets updated to recognise new CPUs and memory configs and thus must be downloaded new to recognise the new hardware in a new machine (otherwise it can’t recognise it properly). With Memtest sure but CPU-Z is something you actually need the latest version of when you first fire up a new PC.
OK, so a bootable thumb drive rather than a read-only ISO image?
I mean, it should be possible to give it an update function which you can run from any utility host, rather than requiring a live install at the moment you want to test a new machine.
That update function could do normal package management and repository things with digital signature checks, etc.
And it could be done ahead of time to support sneaker-net scenarios, i.e. where you won't have networking on the new machine that is being burned-in/validated.