Hey man thanks a lot! So we have checkboxes all around. We mostly use (Unity automatic compressed grayscale) textures. By default R,G,B are using flat colors. We can turn on Use Green Channel as emission, Use Blue Channel as Alpha, and Red Channel is always used for main color, But we can also check to use LUT texture. In case if we have on texture Emission and LUT intersecting in texture, the Emission is Added on the top of LUT colors. (also if channels are different than we use 16bit compression).
Hope this makes sense