Underground Beacon (Deep Dark City loot)

A new item found in the Deep Dark Cities could be something one can place on top of a beacon or somehow combine with a beacon to create an underground beacon. This beacon would work like a normal beacon, but it would have smaller vertical bounds for its range and it would also work with solid blocks above.

This new item would fit the theme, since it makes sense that in the deepest structure in minecraft one can find such an item to make underground beacons. It also wouldn't be overpowered because it is hard to get (because of the warden) and could be extremely rare. With this item you could set up a beacon at bedrock height without having to dig an annoying one by one hole to the surface, which is even more annoying in 1.18 since you have to dig 64 blocks more than before.