Since we have weird shit where it shouldn't be (mineholes in cellars), let's put weird shit where it can be.
We build 4 story stone towers underground in tight cave entrances, so we should be able to cut out the middle man in the "dig deeper" magic and just dig deeper literally.
Even if it came at no quality boost besides random nodes, it'd be a great addition for all the dwarf people. Could even produce curiousities.