i Believe this would be of great help for creating Horror on terror missions if an enemy is spawned on the roof of Dev-selected buildings. it would also create more of a varied tactical situation for the players if they go up to a building and "Ah Snap plasma fire from the ROOF!!!" "Lets Breach that building" i kinda miss clearing buildings in X-Com Terror from the Deep. but yea unless i am mistaken there is no way to do this atm. other this Hoping the Ai will decide to enter the building on there own. besides ATM i have NEVER seen an enemy take any height advantage.
TLDR:
1. When Creating Submaps; Placeable spawnpoints in the submap.
2.Creates Better Gameplay me thinks.