This entry is kind of outdated, as I forgot to publish the jumping results on my Hackaday project page... Even though I thought I'd add a short note on it, just for the sake of completeness :)
After completing the test stand I managed to get the leg jumping for endurance testing. The setup consists of two active actuators and one actuator being just an additional weight that the robot's going to carry anyway. It wasn't active as it lacked the control board. Even without it, I was able to test the two actuators that are most susceptible to mechanical failures i.e. the thigh and tibia motor. The leg completed the 1000 jump goal without any major issues. What's most important the actuators were completely fine (the sungear was the part I was particularly worried about).
Here's a short video on the jumping test:
Currently, I'm working on powerboard and control board PCB's and occasionally milling the rest of the parts needed for 9 more actuators.