The one I was involved with could never jump like that. My guess is that umbilical, at a minimum, carries power. Based on what I know, I cannot imagine the robot doing what is shown on these videos while loaded with the two battery packs that are part of the design.

Please keep in mind that this is a single data point. I am sure there have been many successful builds. It's a nice design. I was not intimately involved in the original build of the robot we dealt with. I was involved in a complete tear-down and reconfiguration to make it work. As I mentioned, this led to the design of a lightweight quadruped that is fully CNC machined and uses more powerful and capable customized drone motors.

I'd be curious to learn more about the motor selection for the complete tear down and rebuild. One of the biggest buys of the Solo (in the article) design is the 'high bandwidth' current/torque control, and the price/performance seemed (at the time) to be pretty great.