There's another possibility. These reports seem to be coming from a very specific class of pilot. Not just military pilots, but those flying the fastest aircraft. Not from commercial pilots or people just in general watching the sky. (Plane spotting is something many people do). I see one obvious possibility: Accelerating like that is a huge physiological strain, and may very well cause artifacts in vision.
For something like the FLIR footage I'm similarly skeptical. Artifacts can appear there as well, and frankly if some unknown research group or ET is able to mask their presence in the visual spectrum, heat signatures ought to be easy, it's tech that already exists.
In some of these cases, your theory requires multiple systems (multiple human eyes, IR cameras, radar) to experience corresponding simultaneous glitches - sometimes aboard multiple craft, some of which are surface ships!
One of the incidents was picked up on radar both by the missile cruiser USS Princeton and (faintly) by an EC-2 Hawkeye radar plane. Those radar planes don't pull high G's, and last I checked the USS Princeton sure the heck doesn't.
Sure, but given thousands uponn thousands of flight hours, multiple simultaneous issues can line up. It's the swiss cheese model of systems failures, a fascinating way of explaining complex failures. Basically it says that if you have the potential for lots of small failures, they may on occasion line up and cause something quite a bit bigger.
It's certainly seems more plausible than a phenomenal that no other commercial pilots, plane spotters, or even military pilots flying slower aircraft have reported like this
If these kind of incidents aren't optical illusions or equipment malfunctions (two very big if's!) then the next most likely explanation IMHO is that these are drones being used by foreign nations to probe our nation's defenses and/or send a message to us that they have some very advanced unmanned aircraft.
If true (big "if!") that would explain why only military pilots have reported these things.
Except that, while the acceleration may cause these physiological issues, it isn't constant. The planes are at cruising speed when these phenomena are observed most of the time. And it certainly doesn't fit that it would be required in any case. If it's caught on FLIR that could occur regardless of speed or acceleration. If they see something stop and reverse directions there's no reason a commercial pilot couldn't. For that matter, there's no reason that millions of airline passe gets a year couldn't, but they don't. Even at higher altitudes and faster speeds, passengers and pilots of the Concorde, when it was still in service, didn't see these things.
There are simply too many ways to explain these things without the inconsistencies of attributing it to some secret research or ET type of thing. Believe if you want, but understand that there are more mundane explanations that fit more of the facts.
For something like the FLIR footage I'm similarly skeptical. Artifacts can appear there as well, and frankly if some unknown research group or ET is able to mask their presence in the visual spectrum, heat signatures ought to be easy, it's tech that already exists.