I don’t know if this will help you but I was going through the same thing and was able to make things work decently well by creating material’s/ material instances with emissive textures so that they show up well. Then I used one directional light with a hue to get a better atmosphere. You can see in the setup for the materials as well as the setup I had with lights vs the setup using the textures. Obviously the one with the actual lights looks way better but considering the limitations of mobile you can get an ok looking replica.