Tic-tacs have not been observed moving "beyond the capacity of modern engineering". Many, many tic-tacs have been tracked to being planes.

And yes, you point out the problem here. Air traffic is highly controlled, and planes are tracked. But the vast, vast majority of "UFO research" does not even bother trying to identify whether or not a "tic-tac observation" is in fact simply another plane. There is a substantial lack of due diligence in the whole affair. It very much is little better than "looks weird, must be aliens". And then on top of that is bad math, just as you've described, which leads people further down the rabbit hole.

Here's the punchline. If there was legitimate strong evidence for "unidentified aerial phenomena" that represented proof of vehicles operating beyond the capacity of modern engineering or our understanding of physics then that evidence could be published in peer reviewed journals. But it's not, and the major reason that it's not is because universally this "research" represents folks not doing their homework. If you are sloppy and you're not doing your due diligence then of course it is easy to come up with outlandish numbers and an absence of conventional explanations. If you don't bother doing the leg work to track down conventional explanations then they won't bother to get in the way of your extraordinary claims, but that doesn't make those claims justified.

This is the problem, almost no one is doing the work rigorously, and when it does get done and something that UFO enthusiasts have been pushing as "unexplainable" is explained the result is that there is no publicity for that explanation. Even more crucially the UFO enthusiast community does not use that as an opportunity to revisit their assumptions and the level of rigor they need to put into such investigations, instead they just sweep it under the rug and say "well, what about THESE observations?!?!" with another pile of videos that have received the same half-assed level of "investigation" and show nothing new or interesting.

"Tic-tacs" are the perfect example here because you would think that after the first handful of "we think this thing that looks like a tic-tac is an alien spaceship" videos were shown to be just regular jet aircraft viewed at great distance (often identifying the exact plane being viewed) that people would then start understanding that when you see something that looks like a "tic-tac" in the sky it is probably just another plane because that's what planes look like. Instead it has not caused that level of rethinking because UFO enthusiasts generally lack any hint of introspection or ability to follow logic.