If they did reverse engineer these UFOs, they must have kept it very secret from the NASA SLS team, and EVERYONE at Boeing. If they secretly gave it all to spaceX then maybe we get a _slightly_ compelling argument…
People don’t invent an amazing thing and then keep it secret to make a profit. they patent it and make a product or license it.
I am totally willing to believe they managed to keep something secret. Hell if it’s true it means they actually did a pretty shit job because everyone knows the word ‘Roswell’
But I don’t buy that after 50 years they haven’t made a single useful thing out of what they found. Where’s my flying saucer damn it? Where’s some new amazing power source that any craft getting here must have been using?