Nope no sarcasm. And my theory on the efuse is I've used them before so know what they do (make sure electronics don't cook themselves usually) and have had my dx open a few times and haven't come across the chips.
It's time to blow this scene...
As I understand it, the eFuse isn't a seperate component, it's an integral part of the chipset. It's probably somewhere on the CPU die. And an eFuse can have more than just the function you mention.