Oh my gosh, well done! I know what you mean with Swing on the Spiral and Step Aside. I know Step Aside would be very difficult to speed run consistently because of the random degree, but if you're patient, one thing you can do is hover on the last conveyor belt before the enemies and just wait to line yourself up. I know it's difficult to sit around waiting, but for that room, it's what I would do, myself.
As for Swing on the Spiral, there's actually a bit of a shortcut. If you leave the room to the right and come back in, the platform is in a position where you land on it if you just walk off the edge first thing you do. I originally had that room's checkpoint in the previous room for that reason, but I felt having to switch screens after each respawn was annoying on its own, so I left that little trick in there for the player to figure out.
