Could you point me to any UFO wistleblower from govenment, military, science, etc. areas that revealed exact technical details about UFO. I mean really technical - not somehing like "it could hover silently!" or "It could turn at 90° at high speed!" or senseless drawings or descriptions of exterior or interior. Something like exact weight, power source output in Watts, maximum thrust in kN, something like "Power source connected to the engine with a cable/pipe/whatever with diameter/cross-section of ... <- exact value"? Anything like that?
First thing that engineer, scientist, military will do with unknown technology is to measure it. And it is not about dimentions, it is about all possible parameters. Also he definitely will try to find and write out distinct parts interconnections and think out a way to categorise different distinct parts, even if he have no clue what it is and how it works. And that are the things that any real whistleblower from aforementioned institutions will wistleblow. They just can't be unaware of that things if they really tried to use, work on, reverse engineer or study that UFOs.
What I find very suspisious, apart of complete absense of known technologies that appeared from nowhere without any traces of preceding technologies, is that there are no any technical details about UFOs governments presumably possess from any known to me wistleblower.
Apocryphally, yes.
Tesla is reported to have built one and drawings of another one were found in his papers (at his museum). https://www.quora.com/Did-Nikola-Tesla-discover-how-to-invent-a-UFO-or-any-kind-of-flying-craft-If-so-why-did-they-hide-this-from-the-public/answer/William-Beaty
Precious little detail on specific workings though :( He told the newspapers not to be surprised if in the near future they saw him floating about in a flying machine no larger than a bathtub which did not utilize bernoulli's principles.
Of course there is this old chestnut too :
https://en.m.wikipedia.org/wiki/Avro_Canada_VZ-9_Avrocar
There are a great many other anecdotes about the specifics of building flying saucers, but i’ve forgotten them (and did not find them credible). Speculations on the nazi bell, and counter rotating vortices of “red mercury” and the like fall in this category.
Good luck on your search, and let us know if you find anything!