Just a random idea here. Adventurers should have vastly inferior maps to nobles. After all a noble might very well have his own cartographer always keeping his map up to date. And adventurer probably has a crude hand drawn map. The adventurer's map could be sepia toned, and changes to realm boundaries could be delayed a couple days (could lead for some interesting mishaps "oops I thought this was still my realm")
I think a more rustic-ish aesthetic is a cool idea. Ingame drawbacks are a bit meh though because of what Egamma said.
