We were talking about SDF maps in the old thread. It's essentially the de facto way of handling custom normals for the face nowadays. If you have no idea what I'm talking about, when Arc System Works or CyberConnect2 or whoever make their models, they make certain cuts in the face geometry that allows them to control the shading on a vertex level. This is why their faces look super clean and might 'snap' when the light source is rotated. Problem with this method is that this custom shading breaks the moment you deform it. There's plenty of 'fixes' for this like having a proxy mesh to data transfer normals from in blender or fixing this on a per-frame basis like ArcSys/CC2. The SDF approach bypasses all of that by handling the shading of the face entirely through textures so you can deform and distort the face however you want and it'll still maintain the shading you want. miHoYo games have been doing this ever since Genshin Impact. It's a relatively new technique but it's increasingly looking like the go-to because of how much easier and faster it is compared to custom vertex normals.