Experience versus science
Interesting topic again.
Nick stated : "viruses do not care how cold you are!"
The article states (imho): "Cold may reduce our defensive system effectiveness, when infected"
I would infer : "if you are not infected, cold (for not too long time probably), will not infect you"
Back to the topic : "in clean air VRS will not occur, if staying out of the area's shown in Nick's graph", so exceeding 30kts, 300 fpm should pose no problem. I also believe this.
But similar as in the case of a cold, you may be affected, meaning that real speeds are not what they seem, since at slow speed moving air masses may significantly change these speeds, even if this happens only momentarily, too short to be picked up by slow instruments.
Furthermore air may not be clean, for instance main rotor takes in some disturbing turbulence from tail rotor, a case that is not covered by the VRS model (as it assumes clean air)
So using "mothers rule" to keep for instance within 30/300 is probably not only well intended, but also correct if one has to assume some extra disturbances will occur, disturbances that may not be anticipated by the pilot (similar as not knowing you were already infected)
Doing a steep approach over a nice big runway, is different from doing a steep approach into an area with obsticles around creating non laminar air flows.
My 2 cents...
Added : I also do believe that (unanticipated) tail winds are one of those disturbances, see my earlier remarks/questions. It would be interesting to know what Nick's graph becomes when flying backwards for instances. My feeling is that margins may get slimmer because of the possibilty of tail and tail rotor influences.
d3