you could PBR render to preview with smooth normals. but honestly for the best quality possible, just do not decimate. unless the meshes are ridiculously dense i would just bake with the highest geo possible, cuts out any errors that might come from decimation.
Thanks, I tried that and I also tried remaking the function inside the material itself. Sadly I still get the error and crash. I can use it once, but I can't use it again later to combine it seems. This is the function nodes only remade in the main Material. If I only use it once for the top one, everything works fine,…