I've noticed a lot lately that natural-tiles are repeating in missions. It kind of kills the immersion during a mission. So, say if I'm in a corpus mission that has an ice-cave; the Ice cave will have a corridor attached to it that leads to the same exact same ice cave.
Also, during Empyrean battles versus Sisters & Liches, two different Sisters or Liches will use the same exact phrase. For example, during the Lich encounter Empyrean mission, a spawning Lich might say: "Ten-O, that's my score when this is over" or something like that, then the next one will say the same exact thing when it spawns.
It would be better if natural tiles weren't repeated. A natural ice-cave is highly unlikely to be repeated twice in nature. Whereas a corridor is a room for transportation and could be made infinitely, since it's a man-made structure, and therefore, it would make sense if there were many of the same corridors on a specific tile set. Then, if Sister & Lich phrases were on a loop, or at least non-repeatable, that would make those situations a bit more immersive and entertaining.