Does Post Processing Stack optimized for mobile game development?
There’s no definite answer to that question. You will have to profile your game to see if the post-processing stack fits your requirements. Generally, post-processing is a high-quality effect and therefore used on more powerful hardware. The post-processing stack is also not specifically created or optimized for use on mobile platforms. But individual effects have different quality settings and options which make drastic performance differences, depending on the platform they are running on. A simple color lookup (LUT) will likely be fine on mobile, but high-quality depth of field usually not. But again, it all depends on so many factors, you should really try it out and profile some test scenes with the Profiler. 