I'm no expert on this, but I know that on Metropia Reverse, if you boost and try to fly over the structure towards the end of the lap, rather than under it, then you have to stay further right than you might expect. You can stray to the left and, even though it looks like you're heading straight for the track, you will respawn. It's probably the same on Moa Therma. I think you just need to know where the respawn wall is and you'll be good to go. Pirahpac or someone else will probably be able to direct you to the right video.