Normal map influence now lerps to the tangent space vertex normal instead of lower mip of the normal map. Less artifacts and probably better performance.

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/LitData.hlsl

 
     // THen get Main Layer Normal influence factor. Main layer is 0 because it can't be influence. In this case the final lerp return normalTS.
     float influenceFactor = BlendLayeredScalar(0.0, _InheritBaseNormal1, _InheritBaseNormal2, _InheritBaseNormal3, weights) * influenceMask;
-    // We will add smoothly the contribution of the normal map by using lower mips with help of bias sampling. InfluenceFactor must be [0..numMips] // Caution it cause banding...
+    // We will add smoothly the contribution of the normal map by lerping between vertex normal ( (0,0,1) in tangent space) and the actual normal from the main layer depending on the influence factor.
-    float maxMipBias = log2(max(_NormalMap0_TexelSize.z, _NormalMap0_TexelSize.w)); // don't do + 1 as it is for bias, not lod
-    float3 mainNormalTS = GetNormalTS0(input, layerTexCoord, float3(0.0, 0.0, 1.0), 0.0, true, maxMipBias * (1.0 - influenceFactor));
+    float3 mainNormalTS = lerp(float3(0.0, 0.0, 1.0), normalTS0, influenceFactor);
 
     // Add on our regular normal a bit of Main Layer normal base on influence factor. Note that this affect only the "visible" normal.
     #ifdef SURFACE_GRADIENT