TE: vertical room splitting

[Joey79100]

Imagine creating a hill, and digging a lake in it. Then you want actual water: you have to split the room horizontally. The current way would be to duplicate the room, flatter the floor in the top room where the portal will be, then flatten the ceiling in the bottom room and lower it, and connect them. But the sectors won't necessarily match. And you have to do that all by yourself.

Having a tool to automatically split horizontally a room into 2 at a certain height, and connect the 2 resulting rooms would help a lot.