Commercial plastic extension boards are practically disposable. A couple of minor drops on a concrete floor, and the brittle internal plastic standoffs crack, leaving 220V live terminals floating loose inside a flimsy shell.
Electrical shops readily stock boards like the one that broke. A wooden one like this has to be made to order, but it fixes the durability problem outright. Real safety, though, comes down to mechanical details most basic diagrams overlook.
Past wiring jobs I’ve pieced together from whatever YouTube tutorial came closest to the job at hand. This time I worked through it with AI instead, which gave instructions specific to this box’s layout and a quick check of the wiring before anything went live.