"That is, if these observed accelerations were sustainable in space"
If the observed accelerations of my car were sustainable in space, I'd be able to do interstellar travel pretty easily.
Stack this up with the other crazy assumptions made in this piece (check out the first comment, for instance). You want to assume high tech has 1000G acceleration? OK, you know, sure, fine. But it also moves through the air at massively supersonic speeds without causing friction or sonic booms? That's another separate piece of technology that's basically magic. (Honestly not even sure which I find less believable!)
And then this amazing advanced technology is flying around is moving around on that flight pattern because... uhh... why would any aircraft fly that way again? Look at that flight path. What possible use could that have?
I've never heard even a sketch of a motive that suggests why these craft would fly in such crazy patterns around aircraft that isn't better met by some other approach, that is, whatever goals something flying such an astonishing craft may have, they could simply obtain directly.
The theory that these are "technologically advanced craft" requires an incredibly precise combination of high technological skill matched with utter ineptitude and stupidity, beyond merely "oh we just don't understand their goals". This is not intelligence acting in ways we don't understand; this is lack of intelligence.