Presently, we have to be standing on the ground floor in a mine to be able to prospect a ceiling tile.
So. If I'm atop a building, I can not prospect the ceiling tile - unless I get the ceiling tile in my action window... then run down and stand under that tile on the floor level. Then, from that position, I can prospect that ceiling tile.
I think it's a honest thing to want to be able to prospect from higher floors in a building, the ceiling tiles.
So - if it don't break the game (lol): I'd like to be able to prospect ceiling tiles while standing on higher floors inside a building.