4000ft/min after 3 seconds needs about 3/4 of a g (6.8m/s^2). That would be almost free fall of a sky diver. Oh, the doubts.
To get out there in a second you need 20.3m/s^2. That's more than 2g.
And since I am pretty sure that there isn't a upwind part of the vortex - because the vortex isn't there at 4000ft/min, I wonder what really happens there. Oh, and the VSI only goes up to 3000ft/min.
... and whatever he means with full VRS.