I got tired of my director's chair sinking into the sand while watching SpaceX launches across the Indian River (in FL) so I printed some feet for the chair to distribute the load from the tubing to a circle about 3 inches in diameter. The metal legs slip into the feet with a friction fit and stay on by friction. I left the existing plastic plug in the metal leg. The leg dimensions is 15mm x 29mm

Once I printed a set, I noticed that the feet got in the way of each other when the chair was folded, so I designed some with one edge removed, so the chair would fold better.

I used a bambu X1C with generic PLA for the feet. The STL is for one foot, so you have to clone it to make four feet for a chair, or use the 3MF file which has 4 feet, and prints in the strength setting with 4 walls for a bit more strength.