Sorry me again. Other ideas. Bosses that downgrade 1 random gem to an ore every second. Ones that half income while alive. Increase reload times while alive. So like debuffs while alive making them a threat on top of their actions. Projectiles that make runners walk in the opposite direction for X seconds when hit instead of stunned. An animal that sniffs ores and concerts them to gems or artifacts (very small chance for artifacts) id make it something silly like alligator.
More ideas: An airship building that has cannons like grapeshot, flaming, normal, etc. Maybe could have dwarves that throw hooks at projectiles and reel them in like fishing almost.
Laser could have an upgrade that splits the beam if it hits a falling ore
If something says it's benefits by scientists or whatever, it needs to say exactly how much by and then a total % currently in brackets.
Digger, scoops up a bucket full of gems and drives it back home, then needs refueling. Can be hit by falling stuff which causes it to lose part of the cargo. Upgrade to have turrets on it that shoot at falling stuff.
Breeding program, each house has an X% chance per minute to give a free dwarf. Make it small chance like 0.1% or something.
Driller. A dwarf with a road drill (one that points downwards), causes mini earthquake that shakes ores and gems off the piles (so they roll down)
Treasure floors, just fill the wall with special dens that hive artifacts and big gold.