So, I did a quick search to see if anyone else has suggested this before.. Do not magma me too hard if similar thread exists somewhere, somehow. Probably only doable somewhere waay past army and caravan arcs.
New labor! Research/inventing
Dwarf with this labor enabled and proper workshop build (assigned study could be enough too) would start a research improvements on another labor, preferring a labor he is the most skilled with. Each "research" job would yield hidden points to a randomly picked improvement every now and then and it should take long time untill a research is complete. (Three years for unskilled. About year for legendary?)
Now what would the complete research?
-Minor, stackable global bonus to the associated labor. (Your beekeepers install and harvest colonies 3% faster, YAY)
-Unlocks a new/foreign item to be manufactured.
This can mean an item in raws that never was available for any civ. Lets modders put in useless/supercool weapons that can be researched
-Improves a weapon or armor/bonus to produced stack of items/reduced material cost for an item.
-Improves random material (Steel is now denser, cuts better!)
-New !!Fun!! (So, the researching dorf just put a troll corpse and that other microline together and now you've undead metal troll raging around in your forest)
Now, on the process of research. The tasked dwarf would randomly pick stuff associated to the labor he is researching. Furnace operator using mostly metal bars and such, farmer taking crops and so forth to waste. The results would be irrelevant to the resources used. You might get something useful for nothing or spend 20 gold/platinum bars to nothing real useful!
Some of the research knowledge would be only limited to one dwarf. Say, that grandmaster weaponsmith who spend years and years to study now only knows how to make mauls.
Now, humans would come to offer items for your dorfs to share the knowledge. They and elves could also come to demand a stop on this outrageous research spree, threatening with war. Kobolds would come and steal your knowledge either by kidnapping a child to learn something simple as steel making or sieging upon the fortress with kidnappers pathfinding towards that one genious dwarf who only can make those powerful items.
Aaand if there's magic and research, it could invoke the wrath of titans, fbs and whatnot.
Well there, free to hate or/and love on this. I leave you with one "minor" suggestion
HFS opening up itself. Get enough wealth or kill enough siegers or just simply by beating the place. How would HFS open by itself? By creating a gigantic slade mining shaft from the depths to the surface itself to a random spot in the map before pouring forth yet another wave of angry clowns. Good luck finding enough time to set up a trap corridor.