When you have to deal with hardware limitations on a specific platform, you might have to do compromises .
You have to get a nice balance between Details / Shading and Memory / Processing load.
For that you can take various path: LOD / Baking / Normal Map or even Realtime Rounded Edge Shader.
Still, when you do that it also cost load. From NormalMap in memory to transitions between LODs to even computing for a small shader effect on sharp edges.
In that regard, if you could handle the Hard Weighted Vertex Normal editing in conjunction with Micro Bevel, you can achieve pretty good results with nice specular or reflections.
This without any Texture or Shader and you can even get a better result than a badly baked NormalMap with wobbly effect on flat areas.
Here are my modeling experiments for our current Unity AR / MR projects at MetaVu Co., Ltd. using my own VeNom Kit
• No Normal Map Baked
• No Rounded Edge Shader
• 1 step Microbevel to smooth out Sharp borders.
• Hard Weighted Vertex Normal editing
You can review this project over Arstation.
(click on images for Wireframe details)
Here is the comparison of this technique compared to an automatic smoothing.