Yep. I know of one more. You can nose down/up and get one in on the straight before the finish line which enables to you to follow up with a SS combo off of the hump on the following turn (or off the left side of the track instead if you are in a gambling mood) to skip a little bit of the track before the magstrip starts. I've done it exactly 3 times on HD, and each time I pulled it off, I missed the obvious skip the loop one, so I was never able to convert that into a world record for a speedlap. I tested it the same time I tested to confirm the skip the loop turbo cut still works.
I'm pretty sure that this will only work with slower speeds though. I've never pulled it off in Phantom or Rapier.