@MercFromStalker I'm not sure what you mean - you don't need to edit the levels to create custom outposts, those can be created in the submarine editor. ;) And there is a level editor in the game too, although it's essentially just for modifying the parameters of the procedural level gen.
@MercFromStalker That should be technically possible with the level editor and some xml work, although it is a bit involved considering you can't edit the level by hand, but have to adjust the parameters of the procedural generation to make it produce the layout you're after.