A lifetime in aviation and I had never heard of this until recently. Note that on the test aircraft, the wings were progressively shortened so that eventually the aircraft flew without the wing extensions with no effect on flight performance or stability. It is believed, that when tested, the results were too good and the interests promoting the then emerging helicopter technology, had the project canned.
That’s pretty cool. If you read to the end there is a pretty convincing explanation for why it was never developed. Still really cool though
I remember reading about that as a kid, when I had dreams of being a fighter jock. My thought then was, “Why didn’t someone think of this before? It is so simple.”