Hi, thanks for your bake and comment @pior. Following your steps, I baked to the original BoxSoft with a cage in Blender 4, sadly with same result as before. To double check, I then downloaded Blender 3.1, baked highpoly to un-modified BoxSoft - and it looks good! This makes me assume things in that regard have changed…
Happy new year! The issue I encounter when importing and baking the boxes in Blender, is that the shading is stored as custom split normal data. If I were to remove the data, the underlying shading is hard (Auto Smooth 30°). During the bake the custom split normal data gets ignored, which is a nuisance. When searching for…