Everything below is CC0, downloaded and tiled here so you can see how it actually repeats. Nothing is wired into the scene yet — Forest 1 is untouched.
Material colours read straight out of the pack's glTF files, converted to sRGB, plus the terrain colours Forest 1 currently paints into the mesh.
Left: one tile. Right: 4×4, at roughly the density the terrain would use it.
The path in Forest 1 is a flat brown vertex colour. These are the candidates to replace it.
Alpha decals laid on the ground under trees, rocks and along the trail. Left: the stamp over grass, as it would appear. Right: the raw RGBA, checkerboard-free — dark areas are opaque, the surround is transparent. The three contact shadows are generated procedurally; the five detail patches are CC0 textures pushed through an irregular noise mask.