If you have an engine failure in a helicopter in the red bit on the graph, you’re most likely looking at a crash irrespective of pilot ability. If you have one at Vx in a single, you can’t glide as far as if you were at Vy from that height but if you recognise the failure in a timely manner and fly at an appropriate attitude, I’d have thought you would have enough energy left for some sort of flare, especially as you were re-entering ground effect. Your presence on this forum is good evidence that this can work.
I agree that it’s not a good area to operate in but a fixed-wing graph might not have much actual red in it as you’ve got to have an IAS > stall speed in that config. in order to leave the ground in the first place. Personally, if it looked like I had to fly at Vx from rotation in order to clear an obstacle, I probably wouldn’t even attempt to take off...