Comment by nippoo

eFuses have been a thing forever on almost all MCUs/processors, and aren't some inherently "evil" technology - mostly they're used in manufacturing when you might have the same microcontroller/firmware on separate types of boards. I'm working on a board right now which is either an audio input or an output (depending on which components are fitted) and one or the other eFuse is burned to set which one it is, so subsequent firmware releases won't accidentally set a GPIO as an output rather than an input and potentially damage the device.