My feelings towards jumping off high boxes and stepping down onto lower boxes!
I recommend stepping down onto several boxes lined up if you have them, it will allow you to work on just the power outage of the jump component and will allow your joints not to sustain such high impact landings.
Because once you get to a certain height with your box jumps, you now have to start to think about the safety of the landing. Because injuries occur during changes of levels, planes and deceleration movements. If we could all jump and land on a cloud we would never get injured. So take these steps to ensure that your landing is of a safer protocol and you can help to prevent wear and tear on your joints, ligaments and tendons!