Thanks to robobo1221 for giving me the hint, how to increase the performance for volumetric light by using a 8×8 bayer matrix dither.
At least I try to improve volumetric light, so that it will finally fit into the atmosphere of the shaderpack someday.. But for now, I really recommend to use robobo1221’s volumetric light in his shaderpack. It’s way more optimized.
Give it a try: http://robobo1221.net/shaders/