Ah well, that's what I figured. Shame.
Doing some more maths using my current embark. Just used prospect to find out how much mithril there is; I'm looking at 4755. That's on a 3x3 embark 175 z levels deep. Whee, that'll take some finding. Now, if I remember correctly, mithril doesn't drop ore 100% of the time. So the x4 multiplier is nullified here. So, let's say I find 10% of that mithril, giving me 475.5. I refine it, patternweld it, I get 951 bars. I turn those into battleaxes and get 475 again. These I churn through the weaponry; I'll get approximately 71 legendarys, 30% of which should be masterwork. That's 21 masterwork legendary battleaxes and a lot of processing, mining, and unmeltable superior battleaxes. Even then the 21 masterwork legendary battleaxes I expect might be as low as 5 (or as high as 40, or anything. I could get 71. I could get none) and I still haven't made any armour. I can recycle some of my axes, but I wouldn't want to turn my weaponsmith suicidal so I would sell the masterworks. There's also a huge cost in steel, namely 950 bars, for all the reforging. With 15,000 hematite stones and 45,000 marble this wouldn't be as much of a problem though.
Now, I can see it being sort of high-tech and requiring a lot of work. Outfitting your best soldiers and the lark. Also you can trade for many mithril items from the elves (which has made pissing them off a lot less attractive) but that source is also unreliable. This is all very well when it comes to mithril... But if I wanted to make masterwork legendary candy axes? There's only 2047 stones on my map and obtaining enough to outfit a squad would not be safe, and of course the resource is finite. I wouldn't want to waste a single wafer.
So my point is the system doesn't lend itself to perfectionists unless you want to equip a solitary adventurer or abuse DFhack or buggy game mechanics. When hitting the candy I think I would probably do the latter. Honestly though, I can't think of a solution, and you put a lot of work into this mod Meph so I don't expect you to wrack your brains over this. Can anybody else?