@Boney : Something you wrote about that I really liked is that you identified Laurelorn as having a major untapped demand for charcoal, which the Empire can supply in great quantities.
This is quite smart, as metalworking requires a lot of fuel in the form of charcoal, and Laurelorn considers its trees as, among many other things, vital parts to its defense. It also has very limited supplies of metal ore to use for things like weapons and armor. Lastly, it uses plenty of leather for armor and accessories, but the types of leather they have available are going to be pretty limited.
The Empire being able to supply charcoal in bulk is an excellent symbiosis since forests often represent
danger to the Empire rather than safety, and despite its logging and charcoal production the Empire is largely covered in forests.
But on top of that, Laurelorn now has (or will soon have) access to metal ingots from the Empire and Karaz Ankor. And while the quality of the ingots of the Empire might not be up to standard for the Eonir, it's probably still quite valuable to get it and refine it further to bring it up to standard when you'd otherwise be paying exorbitant prices on what little metal ore is available locally. Dwarven ingots would be ideal, of course, but would undoubtedly be quite expensive.
Nevertheless, the massive surge in the availability of metal ore/ingots to Laurelorn's smiths means that metal gear will become vastly more available and affordable to the Eonir. And with so much more metal available to smith, the demand for charcoal will increase, which the Empire can readily meet the demand of (and happily expand production to meet the demand of).
But there is another possible valuable product that the Empire can make plenty of that would be useful to the Eonir: textile armors like Brigandines. With ample access to sheep and wool, the Empire can produce textile armor far more easily, and textile armor can be both light enough and flexible enough to appeal to the average Eonir warrior while also being quite affordable.
I also suspect certain products will find a healthy demand in Laurelorn due to the difficulty of producing them in a dense forest: things like bread, milk, beef and various meats from animals not available in Laurelorn, gunpowder (there's nothing equivalent to a cannon with non-gunpowder weaponry aside from strong magic; the amount of force even a simple cannon produces is orders of magnitude greater than even the best trebuchet--making it a great tool for killing something like a Cygor or Arachnarok Spider and invaluable for destroying siege equipment from a distance without worrying about counterspelling), vegetables and fruits that don't grow in forest climates, and so on. Like the dwarves finding that it's really handy to buy natural/simple goods easily produced by the Empire since their own goods are so prized by the people of the Empire, the Eonir might find a strong trade symbiosis with the Empire despite their differences.
Not too far in the future, there will be a strong demand for We-silk armor, and while that will be produced by Karak Eight Peaks, the only reason it will be able to get to Laurelorn will be because the Empire and Karaz Ankor keep the trade routes all the way to Laurelorn safe.
We're already seeing the Eonir be pleasantly surprised by the Colleges (Mathilde specifically, but she represents the Colleges to the Eonir too) inventing a magical means to build a trade road to their new ally that can be deactivated at will to keep their natural defenses secure, and by Mathilde (this time representing the EIC) delivering an entire cart full of ithilmar sourced from the Empire for a lucratively affordable price. Karak Vlag has expressed interest in exporting stone/marble to Laurelorn, Thorek is undoubtedly figuring out which groups are the best option for selling dwarven ingots to Laurelorn, and now Laurelorn is exporting very valuable
waystones to two major neighboring polities. And while I don't know if either group has realized it yet, Laurelorn's mages and the Colleges of Magic have found a new market in each other for magical goods and services. The Colleges having a relatively local source of wizards capable of High Magic is a big deal, and the Eonir have access to the powerful stuff the Colleges can make with the various materials and wizardpower they have available (like the menhir that can turn anyone who uses it into a dragon temporarily, or rare and exotic stuff like Ulgu-attuned wood imported from Araby). We might even see some kithbands give a try at forming a mercenary unit to sell their services to the Empire for both novelty and profit (where a kithband's services might be unremarkable and not particularly valuable in Laurelorn, they might be very valuable in skirmishes with beastmen in the Empire's forests).
On the flipside, I wonder when the Empire's leadership will realize that expanding trade ties with the Eonir means establishing broad trade with an elven polity that
doesn't go through Marienburg.