I recently came across an old post where a friend mentioned his binding highback broke. He said only Spark bindings are sold in Hakuba, and I figured Spark highback should be compatible with Karakoram bindings. Luckily, I had both brands on hand, so I tried it out. As shown in pictures, the highback worked perfectly in all positions. I also compared them. The spacing between the two highbacks is exactly the same, and the screws in picture also are identical.
The last picture shows that I also carry these orange silicone straps or some homemade black Velcro straps when backcountry. Once, due to inexperience and numerous conversions, the skins got covered in snow and became unusable. It wouldn't stick and kept falling off the board, causing a lack of traction and making it very dangerous to climb. These silicone straps or Velcro straps are very useful in this situation. I also carry a few cable ties; once, I lost a small screw on a cable tie on a mountain, and the cable ties were a lifesaver.
Japan's mountains aren't very high, but the terrain is complex, and the snow is usually very deep. If your equipment malfunctions, it's practically impossible to get out on foot. Every time, I'm extremely cautious and prepare meticulously to minimize the risks.