From my experience it's same in every ray-tracer I tried. And always been that way. Mostly coming from sky/environment light . Guess it's why they do small quads with displacement + actual bevels instead of hard edges outside of gamedev. Hard edges is a gamey thing. Actually I have seen a subtle hard edge reveling with…
Yeah, the crux of the issue is that a normal map can fake shading, but it can't fake the actual geometry, which is used for shadowing. For best results, the normal map should be used to represent fine detail that doesn't affect the silhouette, while the primary forms should be represented in the low poly. Of course, you'll…