Just looked it up as it happens and there’s more difference in frame weight than I’d realised - Ultimate CFR is claimed 641g, Aeroad CFR is 960g. Which aligns with what seem to be ~300g differences between the Ultimate and Aeroad models at each price point. Looks like with the most recent models the Aeroad got a little heavier (previous model was 915g) so the gap is growing again. Guess maybe Aeroad taking advantage of tweaked UCI rules to have deeper tube sections has added a few grams.
Think it’s still possible to get the Aeroad down to pretty close to the 6.8kg limit with light component choices (the lightest stock model is 7.14kg but that’s with DT Swiss wheels which aren’t particularly light).