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.
Are there ways of reducing the stability of a path (like the reverse of leaving markings)?
Leaving markings is part of what stabilizes the route, footprints and otherwise. You could magically remove such traces and no one would be able to follow the path.
This also implies, correctly that you could use stealth, careful foot placement, or otherwise to avoid leaving a trail at all. You’d still leave body heat in the air as you pass, but with magic, you could even clear that away. At which point, someone would likely need to be within visual distance to follow, otherwise at the first branching, they’d have at best a 50% of following you.
Edit; Thinking about well traveled caravan routes, they would be very difficult to disrupt. Any caravan that regularly runs that route would have it mapped, Which requires some creative mapping, but can be done. Which leads to people finding maps to all sorts of goodies in the caves.
How does mapping work if the paths aren’t stable?