Nick,
Do you recall the crash of a hovering Canadian H-3 which occurred at an airshow....the video has been shown all over several TV programs. The incident occurred when the aircraft was being repositioned from one parking spot to another and appeared to start from a relatively stable hover.....at least in the vertical plane. The aircraft was being turned .....dropped like a stone, impacted terra firma and rolled over. Interviews of the crew as shown on the video were consistent in confirming no mechanical malfunction occurred and the crew stated they had encountered vortex ring state or settling with power....key point being no descent or very slow rate of descent involved at the onset of the problem.
The question in my mind is if it matters how one begins to recirculate the downwash....be it while in descent...or at a hover....it would seem so long as you find yourself in a downward moving column of air and application of additional collective (power) only makes the situation worse....then you have arrived at the point of settling with power/vortex ring state or some very similar phenomenon however you want to name it.
In an ideal test, while in VRS, would not rate of descent vary with application of collective pitch? Higher rate of descent for increase in collective pitch applied and reduced rate of descent with decrease in collective pitch applied. Which is directly opposite of the reaction in normal flight conditions?