Thanks to gunshy, I started to use relax a lot more. However, in the beginning kick, I realized that it didn't work as well if it was in relax, so I was forced to hold.
Lies, you just didn't try hard enough. Also, that kind of jump kick is really common, easy and nooby.
However, in the stance at the end, I did use relax.
It still felt stiff to me.