Picture this: you create a challenge for the player, like in the gif, but you don't want them to respawn in the challenge area. The only way to do this is by using parts that make the ground "unsafe" and making them invisible. The issue is that it takes up a tile space and is very tedious to do, especially if you have decoration already on those tiles.
My suggestion: A sunlight/darkness type tool that lets you overlay an unsafe zone box anywhere you want, and its only shown when in editor mode!