Suggestion for objects; pools. Magical pools, water fountains, etc. radiant colors as purple, green, blue, or just plain water. Maybe even dirty water. Good for caverns , castles, and alchemist lairs.
Yes, this. I'd like puddles of water, on floors or in depressions. Areas of wetness, basically, that aren't limited to the "water table" level we have right now. Of course this could include water, muddy water, blood, oil, and so on.
dirty sewers that are connected to privy chamber. That can be used when you want to sneak into some rich person and don't want to take regular doors that are guarded
I know Fata Morgana enables some kind of pool construction, but ponds would be awesome, and small indoor lakes, too. Specially if can break the water level limit.
And... since we're there... can we have fishes swimming on it?
The artificial pools are great, but how about a few natural ones to drop in a dungeon? Something that the edges match the stone floor coloration. Something a water based creature can crawl out of.
Might as well be able to do pools of lava as part of this. I would think it would only be a simple texture change.
Don't forget ponds and manmade small lakes and the ability to personalize them, too.
Stone carved 'irrigation canal' so that I can build aqueducts