you can detect angles in shader in your engine to select for edges. Its probably possible to multiply a noise on top of that to break it up and look more natural. Not sure what rendering engine you are using, but for most of the big game engines you can find tutorials which will show you have to do basic edge/slope…
Im using tiling textures on large rocks (think cliff faces) and there is a common workflow where when you still need to have edge wear on large rocks, you use masks in conjunction with your tiling textures so they can blend better. Then on a separate texture map you have masks for edge wear, AO, dirt or whatever else.…