If Avax is laying low, he had best gain that fame under another name.
From Avax's explaination and Viluki's background story I think both of you meet my standards. I will be making a paragraph describing Oleg's outpost. You will need to interact with the locals to determine where the expedition is currently and if you can join.
Perhaps Avax is his alias!
are we assumed to have the copy of the charter to join in the expedition or is it more a matter of a couple of freelancers working their way in?
Presently you are attempting to find the group with the charter. Since the Swordlords have heard good progress from this group they have not created another charter yet.
Avax you likely will come in on your own or with a caravan from the Five Rivers Kingdom, your choice. Whereas Viluki could come down by himself with a few other like minded souls, or with the next caravan from Restov. I leave it up to you how you come in and describe it.
I will elaborate as needed.