I'm seeing vertical footsteps motion so I'm not sure if the handle springs are working properly.
If you translate the Japanese it would some that they noted that issue.
Filmpower should do a setup example showing the impact of setting up the spring response properly.
Spring arms can isolate vibrations from vertical and horizontal directions. Different tension will have different natural frequency. Human also has a natural frequency when walking. If the two natural frequencies cancel each other out, the stabilizer will work smoothly. Otherwise it will enlarge the vibrations. Users need to adjust back and forth and practice a lot to get the best stabilization.

The springs can handle the high frequency vibrations better if they are looser, but the reaction period will be longer. The tighter they are, the shorter the reaction period will be.