I see the basic smelter and forge just as generic baseline workshops, not specifically Dwarven, and they fill a perfectly serviceable role. ... What I am taking away from your suggestions though is to expand the range of reactions at Tribal Shop, Slag Pit and Factory so they stay useful longer into the steel/bloodsteel/mithril phase of the game.
Hmm, Bloodsteel is tricky to balance because of course as long as you're butchering your enemies the supply of materials is neverending
But it still employs a lot of orcs in the processing, between the butchery/blood extraction/ashery. I haven't had a good mass production line up in the last few games, do you really think it's a lot easier than steel? ... The demand for Bloodsteel is a bit higher in the new features under Development which you can look at in the orig post if you like, so that might help, although a lot of it is just one-time not recurring costs. If it's still too easy I'd be more inclined to tweak the balance in the numbers rather than a total overhaul.
... My preferred tweak would be to require Ironbone as a reagent for Bloodsteel instead of fresh ash & bone -- this adds one unit of [FUEL] cost plus an extra reaction step -- but I don't like to mess with Vanilla or Masterwork reactions unless I really have to, because the more independent the file structure is the better.
Another idea is to let orcs refine steel into bloodsteel so that the metal line is as follows: rusty iron -> iron -> steel -> bloodsteel (with certain bits of mithril, cobalt, ironbone, etc items). bloodsteel is only as good as steel, not better. But I could imagine adding an mithril-quality metal transmuted at significant cost from bloodsteel. Just have to decide whether it is a metallurgy or mystical process ... hmmm.
As for plants. Meph said that removing various item types (like various types of leather) helped fps a lot. Won't those options revert the situation back to the original state? And those plants do create seeds, don't they? Well, perhaps. I think you press the seeds to get the oil, just like rock nuts. The great thing about Masterwork is the modularity, so you get to decide whether you want FPS or above ground olive oil
You can pretty easily keep just a handful of plants that you like and delete/archive the rest.