[Therion] Drawing the map of a vertical cave

Hello, I am drawing the map of a cave that is so far mostly vertical. In the map editor of xtherion is very hard to distinguish which lines / stations of the xvi belong to which part of the cave, because they are all drawn over each other when seen from above. When adding walls and objects it becomes even worse. Is there an easy way to deal with this? Maybe generating different xvi's for the different levels in the cave and drawing the scraps in different th2 files? Best, Jean-Florent.