I found this actually in a cliff project where I had the cliff really tight, but I actually thought it was because of my Vector Displacement warping, and so just moved past it with different settings.
However I'm working on some cracked mud shaders, and it's reappeared in a more controlled environment. Basically, any straight edge angle facing away from the camera creates line-tears towards the camera. On top of the line issue, shadows aren't working like the did before either with the geometry.
Example here is MPD 0.7 AA 6 SR but the same appears in PT at the same settings. This wasn't a issue with this same cracked shader that I used a long time ago for my dried pond with the bison skull, so it's appeared more recently. I can see what's creating it, there are weird jagged artifacts in the displacement calculation, which viewed directly are just little jagged marks, but when viewed away from the camera, tear through the terrain at the camera.
Is there a way to remedy this without insane render settings? This seems like a bug in approximation of edges. For example, if you have a perfectly straight edge on a planet, like from image based, you get nothing but streaks down the face, rather than a smooth face.