Read this post said:
How is it lacking? I literally explained how spatial manipulation would work in that instance and how he would be able to create shortcuts through spatial manipulation without teleporting. Read the comment properly.
He has consistently shown to be able to teleport/run faster than he can see and definitely move faster than he can keep up with. And no, it isn't. If sans isn't able to throw an attack faster than frisk can perceive he can be caught and killed. Plus we don't even know his striking strength which may very well not be enough to kill frisk especially on a genocide run.
What part gave your interpretation more credibility than saying that it's teleportation? We know for a fact that he can teleport, so I'll just call Occam's Razor and say that is teleportation too. You give zero proof beyond Sans calling them shortcuts. There is zero reason to differentiate him disappearing from in front of you during genocide, him teleporting your soul around, him teleporting back and forth before the "dev room", etc.
He never once tries to make you believe you didn't teleport but walked, not once. Papyrus directly mentions that he hates how he bends space to skip his traps, and nobody else ever acknowledges it. That isn't proof. Because him walking to the opposite direction is not more plausible even if he were to "shorten space".
Seriously, did I miss some proof? All I'm seeing is "there is nothing saying that he is not shortening space instead of teleporting" (asking to prove a negative, burden of proof negates that), he calls them shortcuts (Hardly enough proof on it's own. And shortcut can also mean a way to skip something, so... yeah) and that he is trying to hide that he is teleporting (just false, completely. When you go to the annoying dog's room, he teleports in front of you and even questions why your following him, obviously poking fun at the fact that he appeared before you without moving. Papyrus also knows that sans plain skips his traps, and the others don't react to him at all, so no real argument there, either.)
As for the last part, no. He never shown to teleport faster than Frisk can see. The screen either goes black for a second, or you can obviously see how he teleports you back to your position. And that makes no sense. He doesn't need to throw it. He could grab a bone, and just physically walk besides frisk and stick it up their ass and call it a day. The bones still ignore durability. And when frisk get's close enough he can one-shot them with an undodgable attack, so he could walk up behind him and do that.