What is light teleportation?

"Player is not allowed to teleport or use teleportium (including accidentially) or teleportitus. Holy Mountain portal excepted."

And how to rephrase the rules to forbid it?

Considering the current first run by Derium (with no disrespect to him whatsoever, it is a great run), I think that the problem you state is clearly exposed... Dropping the framerate gives much more time to take decisions and maneuver through the enemies and terrain, resulting in a somewhat unfair advantage, if we only consider the inGame time.