In blender when baking with a multiresolution modifier from this highpoly: The baked normal-map on the low-poly looks like this when using "Bake from multires": These are the UV seams: I thought it had to do with UV seams first, but it's unable to bake round edges anywhere at all, anywhere on the model. I noticed that…
The main differenc i see for 3.1.2 and 3.6.9 is.. the island margins are baked a bit differently bit seem not affect the model itslef at all. Additionaly: since this was done with a subdiv level of only 3 and smooth shading and no seams at all.. Could it be that using 5 and maybe flat-shading leads and maybe too small…
Such surface information transfer is typical of rendering pipelines leveraging subdivision+displacement. This is IMHO precisely why the bake from multires follows the geo of the low : the subdivision at rendering time would take care of the rounding of the base model, and then the displacement is applied for the fine…