CDI Roadkings do give better kmpl than points ignition ones, but that is like saying cancer is better than AIDS.
If you need more kmpl on a Roadking, take off the original Jikov carb fitted on it and replace it with a Pacco carb and set the slide needle on the second notch. Well tuned Roadkings fitted with Pacco carbs on this setting, if ridden carefully give around 32-35 kmpl.
The Roadking feels liberated on the Jikov. If I were worried about kmpl, I'd buy a Bajaj Platina.