I don't know if this is possible with Unreal Engine but what if there was no fog and red sea except in the Shores of Gold area? Instead, when sailing "outside" of the map you appear on the other side. With further map expansions the border could just be expanded.
E.g. Sail east from the Devil's Roar and you'll appear in the Shores of Plenty.
[Upon further thinking about this idea I realized this would just break the whole idea that the Sea of Thieves is just part of the bigger world]
@Grimholde has a good workaround in the comments below.
You can ignore this post, thanks for reading anyway.
