This has been a very interesting thread!

This reminds me of an engine that did the exact same thing. I could adjust the needle valve and get her screaming, but every time it rotated on take-off, the engine would die. As a last resort, I replaced the piston and cylinder. Took care of the problem. Like I said, this was a last resort, because I had good compression. The engine was just "worn-out" and couldn't take the extra load at lift-off, or a nose up attitude.

Now this was a COX TD09 engine, however, it demonstrated the exact symptoms described here. I know that your engine is not as old as was this 12+ year old engine, but it sure makes me wonder if you had a lean run causing your engine to lose efficiency and act like a worn-out engine.

Food for thought, cause it sounds like you've troubleshot about as far as you can go.

Best of luck finding the culpret.