My mind feels broken.
When they said that we'll all have access to the same tools that they used to create the game's official levels, they weren't kidding. Keep in mind that this is lesson 29 out of 33, and most of the track building lessons were very simple and easy to understand, and these are pretty much the most advanced--thankfully optional--features of the advanced version of the editor. Never the less... Wow.
I'm just glad to know that others will do amazing things with this tool set, and I'll just be able to download and enjoy their work.