I tried that first Christ, the biggest issue is that if its not small enough (diameter) it impedes the rotation of the dpad. I initially cut some plastic casing into tiny circles, and used a small dab of glue in the sandwich to provide some height. It slipped with use somehow. I used one of the screw covers and that was ok, but it was squishy. Its definitely possible to go that route, but it seems that the best answer is a longer solid pivot, that's held in place by the dpad itself being forced into the case mold. Maybe a 3d printing pen would work well for such a mod, though I don't have one...
If you try and come up with something successful, definitely share. I still want height on this 3ds pad, and I'm considering my options. At this point, I think a thin piece of strong pointy metal (like a thin sewing needle) could be pushed carefully into the center of the pivot without going too deep, and clipped with diagonal cutters to desired height. The biggest issue with such a sloppy modification is that if it slips during insertion, your dpad is toast. Its too thin to reliably manually drill by hand. .