Most 3D printing rabbit holes have a way of pretending they’re practical right up until the receipt pile starts looking a little too honest. You buy a printer to make useful things, then somehow you’re pricing out hardened nozzles, dry boxes, build plates, specialty filaments, and another roll of matte PLA because the last gray wasn’t quite right. I’ve fallen into plenty of those tunnels, and most of them were fun, but I can’t pretend they were financially responsible. Gridfinity is one of the few exceptions where the deeper I went, the less I felt like I was just inventing new excuses to print more plastic.