Admittedly it was more of a tongue-in-cheek joke with some fact - I've done it successfully 4 or 5 times on systems meant for "production" only after testing on EoL/scheduled for the bin hardware with mixed results - at least two I hit data pins and rendered the port unusable, one the Dremel slipped and ended up cutting a slot through the board itself, and another one you would have sworn was perfect but just didn't go (probably something shorted out I couldn't physically see). I did three good ones after those 5 or 6 failures, at which point a friend wanted me to do all the x1 ports on his board to fit x4 NICs he had, not caring if it was successful or not (he had backup hardware just in case, which thanfully wasn't needed), followed by another friend with a server he wanted to put a GPU in. If someone handed me a board today I'd feel fairly comfortable I could do it without issue; I still wouldn't exactly recommend it to the faint-of-heart or those without steady hands, but once you kinda 'figure out' the right way to do it with the right tools, it's pretty straightforward.