I've previously printed custom lego pieces for the Lego League kids, that my wife has at work. I'm using a Creality Ender 3 S1 with 0.4mm nozzle. Though I've not tried smaller parts. They were 8x2 units and 2 or 3 units high. They have the name of the kid on the side. It took some tries to get the tolerances good enough, but now I can print them with normal speed and minimal post processing.
So I think it depends on what pieces you want to print.
How could one protect electronics/hard disks/etc from a Crrington type event?