As others have mentioned; there's no way for it to tell you how much additional damage it did at max stacks. For example, if you Syndra Q with liandries, it would need to snapshot the AP ratio of both your Q and liandries, as well as your other runes and items, then simulate the damage as if you didn't have the adaptive, and do that every single tick of damage. This is also not counting other outputs that Conqueror helps: Healing/shielding that scales off AD/AP. Riven/Swain for example get a lot of value from conqueror that isn't tied to how much damage you deal. It's just not really feasable.