While mapping is a very organic progress, you sometimes lose the objectivity when it comes to size and length. Instead of knowing when it's time to stop adding more, you simply think "Wow, this is something I could add here as well". This is what happened to a lot of maps in Chapter 2, especially Operation Schlangenkopf (C2M3). While we were watching various gameplay videos on Youtube (specifically ZikShadow and MrIcarus), we simply went overboard, putting more and more stuff into one single map. Players needed almost an hour to complete one map. This is simply too much and absolutely not satisfying.
Shortening Maps
We needed to check all the maps (from the beginning of Tunis up to the Astrostein missions), and find out what areas are needed to keep the tension and gameflow, and what portions of the map could be removed because they do not add to the overall experience. C2M3 was a very good example. As soon as you collect the yellow key, you enter a huge area of containment and underground labs that just doesn't add anything to the story or the gameflow. It's just there. Removing it was the logical consequence, and that's what we did with a lot of places. Instead, we tried to add something in the spirit of the map, or tossed areas around to make the progress more fluid and organic.
Improving Maps
Sometimes, if you play your own maps again after a while, you start to think of different approaches, different solutions, different possibilities that will make your original vision more convincing. The second half of Operation Astrostein is a very good example of how a map can still improve, despite it already being finished (Yes, this is a spoiler; I hope you've played Chapter 2 already). When I first created the map, I had a very clean futuristic design in mind, just like the original Astrostein episodes. After visiting New Berlin again however, I thought that this approach wasn't realistic. I imagined this place to be more dirty, more dangerous, something between Cor