Vectored thrust is heated air. Those plumes show up on FLIR, but as the pilot noted, this vehicle didn't show any plumes.
When you mention "TODAY's secret technology" you're not citing anything but your imagination.
You also didn't explain how you're fueling this thing for hours and hours. Explain.
Give me a cool $billion and I can vector thrust without IR plumes. It doesn’t take alien outer space technology, just expensive secret technology. Just like as happened in the 1950s, 1940s, and 1890s.
As long as we’re bringing up stuff that the other guy doesn’t talk about... Then YOU explain how the 1890s and 1940s and 1950s technology that we had available could explain the ORIGIN of UFO sightings.
Then once that info is in proper Occham’s-Razor context, I will happily address your sophisticated but incredibly narrow bullshiite argument.