Timing/syncing the hands going back/down against the forward advance of the pelvis is what the goal is Imo. 2 moments of separation. the hands/shoulders/torso first and the pelvis/torso second in that order. sequencing those moves can make the launch sequence automatic. as long as the hips don’t rotate early.
the thought is that the smaller segments take longer to get back to ‘square’ (farther to travel) so they need to sequence sooner. Since the pelvis has the shortest distance to travel it should load the latest. The hands having the longest distance to travel should load first.
edit: if you keep the energy inside the back leg, ‘loading‘ should stay in balance during the negative phase.
What intrigues me about this gif is the gathering. he gets back which turns into behind him, controlled and balanced. Notice the head, still As he gets back.
the upper needs stability to rotate well on top of the lower. So yes both feet in the ground is optimal. Or you will need to use another power source. Like casting.