Excellent layout and presentation!
The navigation mechanic is neat, though it might be a bit repetitive if its always just 1 character in the party making the check. It would be cool to have the party collaborate more.
I think the core structure of the adventure is a little grindy. There's not a lot of decisions for the players to make other than pick a hex, go there and search, hope to roll well on result to get some signs.
The biggest thing hurting it is the random result roll after searching a hex. I think signs could have been incorporated into more of the hex locations (similar to the orc camp, which I think is great). Or at least have something in each hex that can improve the result roll. This gives the players more direction when within a hex, at the moment they feel a little aimless.
A stronger time pressure in the adventure would be cool too. For instance, incorporate the orc faction hunting for Dr. Oiram more thoroughly.