Was checking around a bugged anthill in my world, and eventually decided to reveal the map with debug to see what was going on. While it did work, it revealed a rather large chunk of stuff to me. Is there any way to reveal individual overmap tiles so that I can check localized stuff without having to reveal an entire overmap’s worth of stuff?
The clairvoyance artifact you can spawn in will automatically reveal what you would see with full vision (roughly a 7x7 area around you). You could also long distance teleport, which lets you teleport to any overmap tile which, obviously, maps that tile.
Otherwise, just save, reveal the entire overmap, then Alt+F4 to close the game without saving. When you load back in you’ll be back at your save point with the map obscured again.
In retrospect long distance teleport + clairvoyance artifact is probably what I was looking for.