If Averland sides with us Sollanders' then I would be happy to let Averland keep the BlackFire pass.
We could do with the extra forces that Averland could provide.
Averland has always had the Black Fire Pass. What was being discussed was military assistance in return for being able to maintain all of the land underneath our current jurisdiction, without a fight.
I currently have two Averland forces during the current GW WFB calendar, fluff wise.
The Aver River Regiment, based just west of the Moot, south of the Aver River, and north of Bieswang, in and around the small hollow between the woods and the hills (the town is yet to be named, but I've been contemplating), is likely too busy patroling the Aver River between Averheim and down along the Blue Reach to the World's Edge Mountains to be available. Besides, they have a mercenary Wissenland greatswords unit that works with them.
However, Graf Heinrich von Furstenberg's mercenary unit might be willing to provide aide, as long as he knows that Averland will not be threatened by Solland revolutionaries. He and his men would need to be appropriately paid.
(And yes, I see the map now, too. Not sure what happened.)