So you can overwrite the GPT header, thereby bricking the device, but not one partition? :P

And in any case, it is trivial to skip write errors when restoring, as it is to extract individual partitions from a full eMMC image.

Less trivial (and possibly impossible) is to combine different partition images into a single image, because, among other things, you are now missing everything that wasn't within partition limits. Which I would say normally would not be a problem, as there should be no important data there, except when ...... manufacturers do weird things, like the above.