Cobaltseed has succeeded. I have not turned the HFS into a luxury resort, or even completely walled off the caverns, but the only serious threat in a long time was when I let out the HFS (not having read spoilers), and my military managed to kill it before I lost more than half my dwarves, and no tantrum spiral ensued (hooray for waterfalls!). I'm not even producing food anymore because I let food production get so out of control we probably have a hundred years' worth stored. I make everything out of green glass and obsidian, both of which I can make more of. Okay, and steel, which I would eventually have to trade from the dwarves once my layers of marble and magnetite ran out. I haven't even needed my underground tree farm because I'd made all the steel I've needed by the time it was ready. Goblin sieges get cast into obsidian for easy iron collection. Forgotten beasts with syndromes get the same treatment. The FPS is getting low, and I'm not that interested in megaprojects just now.
In short, I'm done with the fort. I want to start a new one somewhere more exciting, and I'd like all the history I've built up with this fort to appear as legends in the next one. But abandoning this fort when there's nothing wrong with it just seems wrong. Shouldn't it be possible for this fort to go down in history as a new permanent dwarven settlement? Maybe I would need to become the dwarven capital first, but it would be nice if I could be a source of migrants clad in giant leopard leather for future forts without the fort falling first...