Fifi hooks.for gear bags. Not for hanging yourself off, obviously, but handy for a tat bag or rope bag for later hauling up behind you on multi-pitch climbs. See how you go with weight limits - they're 4mm thick but you could lift the z value in your slicer to give them a bit more strength. I use them with paracord but they should fit 5mm cord.

A couple of designs I'm playing with, both with obvious inspiration if you know your gear.

I suggest 3 to 6 walls, and 50% fill, depending on strength requirements.Remember walls do a lot more than fill for strength.