Imho (yea, I know, but here goes);
CV should not be able to roam independently but should require supply ships to occasionally steam out to resupply them. Even a CV without air operations still needs to be refueled from time to time, needs provisions for the crew, etc. In addition, the more air operations that are conducted, the more av-gas would need to be steamed to the CV group to keep the birds fueled up. At short distances, we can use the supply barges (which are already in the game) but at longer distances we can use ocean going cargo ships.
What would this accomplish? It would; allow hidden CVs to be found, create a strategic type of gameplay by hunting down those cargo ships, and overall create more play and targets for a bomber force which has little to do.