I was just thinking if there was the possibility of a butler bot being able to replace a block with another? Like say you accidentally spill water from your pond or you dig a block too low and the water shifts. You can replace the hole you dug (the water in it) and it would place a block in it but drain the liquid so you could use the bot to place it somewhere else. Maybe even have it for blocks but it can only replace one block kind with another. So you drag the bot with fancy backdrops over the normal ones. It would replace all the backdrops if you dragged over them, but if you were to drag over the window, nothing wold happen. If something I said was unclear, please let me know and I can try to re-explain it.