Fundamentally this is the same problem you have when texturing a landscape - you have a relatively low mask density and you need a very high perceived density of information. The same bag of tricks you can find in the billion youtube videos on the subject (ie. noise + height blending between tileables) are applicable and…
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.…
Lots of things you can do and it depends on the situation, so images of your exact problem are best general things to try: find a larger image to use for mask use a noise brush to paint the mask manually use an upscaler (free on internet) to increase resolution of an image use geometry to screen view of large areas layer…