I think you are right! Binders are mostly carbonhydrate, so they don't contribute to nitrate and phosphate in the water. However, I believe the presence of excessive available carbohydrates may have some impact on the bacteria population in the aquarium.
In terms of the digestability of proteins and fats, that's another issue all together. Pellet quality is an area where more discuss should happen. Let's keep the discussion going!
Fair point. When I write this I was thinking about the idea of feed conversion ratio. In a way this is more critical for reefes than fish fa