While the caves are non-Euclidean and infinite, any given path once traversed, is stable for 1d6 days, with modifiers based on the number of people traveling said path, and any markings they leave.
This means that if something nasty crawls out of a monster nest deep in the caves, there’s a good chance that its friends can follow. Conversely, an adventuring party can delve the deeps, follow the spore trails, and clear out the danger before more makes its way to the surface.
This stability, coupled with the fact that any cave diver is likely to return to their home canyon (if they survive the depths) means that a secondary form of adventure is available. Trailblazing new trade routes.
The normal method is to simply enter a cave, take the first turn available, and then make your way back to the surface, then use the sun and stars to see how where you are North to South. Then repeat until you have a useful trade route.
Most useful trade routes have 3d6 stops above ground. Finding a faster, more direct route, can lead to riches.
Maps work by showing which turns to take, and importantly the distance between the turns, with guides on where the scouts should step. Think of it as a list of vectors and distances.
Paths may not be stable, but if you follow a guide (either a map or markings/spore trails) you should come out of the rock face roughly where you’d expect to.
Take a wrong turn, or walk around the wrong side of a cavern, and you lose the trail. Even with a map, there’s a chance of losing the trail, at which point you either have to backtrack, or start exploring randomly. This should be a result of the Scout’s tracking and or navigational skills.
Basically, this is so that players have a degree of agency in their cave diving. It’s their rolls that see them safe, not GM rolls. (GM rolls are for encounters in the caves, things that might also be traveling those infinite paths)