This uses a glitch(?) called PCS (portal cutscene skip), a glitch where you can skip the portal entering animation by jumping into it from above and landing into the portal dead center. The reason it saves so little time is probably because the jump height is so high but I managed to save time anyways. I'm pretty sure you can squeeze extra frames out but I'll leave that to @KlimbRio1 (or any other souls brave enough to do this) to improve this TAS. As for the other categories... I think you can get it. I probably will try to go for these over the weekend but resyncing the ending is a pain so it might take a while. I think you might be able to squeeze even more frames out of the beginning portal by abusing the velocity-maintaining mechanics more, but this is good enough for today. Update: The glitch seems to be pretty inconsistent so I'll probably have to figure out how to make it more consistent... Update #2: I'm pretty sure this has to do with how many portals you entered as well, since it doesn't work for invincibilityless, and in that category, you do enter the beginning portal, unlike any%.