What would the Shadow Plateau import? What would the Shadow Plateau export?
It is not a major region, so this is not defined in the Guide to Glorantha.
The Shadow Plateau was devastated by the destruction of the Palace of Black Glass, but that was hundreds of years ago on the current timeline. There is a sizeable population of Uz there, 41,000 (though this makes the plateau one of the least populated troll realms) and they should trade
(a) with the Kitori / Troll woods,
(b) with Orlanthi humans (some of this being mediated by the Kitori), and
(c)with the other troll realms.
I can imagine these flows of goods:
Human to Uz: Livestock, ingots of bronze (the Uz have Zorak Zoran smiths), worked bronze (weapons, tools, scales for armor), other materials not found on the Plateau like ivory, rarer non-igneous rock minerals, some scents and perfumes, spices.
Other Uz realms to Shadow Platau: The Shadow Plateau will import spider silk from Cragspider's realm, and giant bee products from Dagori Inkarth where the Vale of Flowers is. These places would seem to have distinct advantages in production, not to deny that some Gorakiki - Bee and Aranea initiates may live on the Shadow Plateau.
Troll Woods to and from Shadow Plateau: I imagine the Kitori as either self sufficient hunter-gatherers, farmers, herders. or middlemen conducting trade southward with Heortland and Esrolia. They will produce things - but with a population of only 5,000 their economic capacity is limited. They would have an advantage in production of insect products, and another advantage in pottery and redsmithing for Uz customers, because the human Kitori won't have the instinctive aversion to fire that Uz do. even Zorak Zoran Uz.
Most of the Shadow Plateau's Uz population is "subterranean" according to the Guide. But the Plateau is vegetated, so I imagine these Uz as mostly hunter-gatherers, living fairly well from a large area. Twp places are listed as urban in the Guide.
I can imagine the Uz of the Plateau producing and exporting a variety of insects and insect products; and fungi, some with medicinal or hallucinatory value; and of course lead, what else would you get from the lead hills?. Troll drinks too, of course. And since Belintar's death, they have been raiding.
What other economic aspects of the Shadow Plateau can you imagine?