Transition From Hard Style To Soft Style (A No_Know Say)
Take a rigid plastic cup [because glass can break if it hits something the right /wrong way] (a yielding cup can be a challenge to hold as force changes as you move it in your grip), put water in it (water cleans up more nicely if there's a spill). Move/swing your arm from the elbow or the shoulder to make a circle where the cup goes bottom-side-up and up-side-down.
Whip use of force seems to involve transition too. Hard to soft? More at rigid to yielding. Relating to whip power is speed [This might seem weird since you think what you were doing dealt with fast]. Tension to deliver Power. Tension to conduct strength faster because the muscle is closer. I can see this. But when startled we go full body tense and are very still. Close muscles act as plate mail and shield our underneaths some. To punch with Power and move fast seems to actually be Hard and S oft. But Tension all the time approach can be draining and leaves your muscles looser than before. thus less responsive after a while because they are stretched when forced long while tense.
I's not soft so much as deliberate momentary transitioning tension. From a firm-Stable base as Mighty B mentioned with stance, shift like a Tsunami and the rocks falling into the ocean. Still motion still begins the force wave. Through your articulations/joints direct the wave-transferring it from section to section (each section releasing the tension passing it along. Pushing it with each successful directing out to your fist and Power like the water in the cup forced to the end of the movement. Fast, with movement that does not falter or get in its own way or stop the water stays in the cup (at 75%-85% or less full).
Greater understanding is perhaps gained from correct movement. The practice/training...the Look is select movements that allow continued movement with low to no spilling. If you get wet, then there's a better way to move a different direction to guide a different balance of tension transfer.
Circle-ish, figure eight, infinity symbol, rounded curving movements might give an indication of "weight at the end of a rope."
No_Know