I was pleasantly surprised to see today that he had brought the slingsword back out, as a basis of comparison for a wooden sword he had made from European dogwood, the hardest wood that grows in his area. The slingsword shows up just before 8:00 in the video.
As far as I'm aware, this is the first time a blade of mine has been used on a tatami mat cut. His comment: "The tatami felt like NOTHING AT ALL when I attacked it with your blade... great work for sure." 😎