No, you have to synthesize that conclusion from the fact that the desired pressure differences for equal feel were 0.5 bar between each tire size (top right paragraph on the first page of the article) and the result that a drop from 7.5 to 5.5 bar in the Conti 28 mm tires gave about a 2 Crr increase (on page 4 just below the picture of the blue Schwalbe tire gauge, not the caption but just below that). So assuming linearity, 0.5 bar reduction would give about a 0.5 Crr increase. When you adjust the results on the bar graph for those increases in Crr with decreasing pressure and apply the implications of the error bars, the differences between the results for the three tire sizes evaporate.

Some of the data in the Slowtwitch article you referenced says the same thing. Look at the spacing between the 28 mm tire graph line and the 25 mm tire line. Notice that they are spaced just about 0.5 bar apart for points that are at the same Crr level. That doesn't hold for the 25, and 23 mm tires, but isn't far off for the 23 and 20 mm tire pair. And the Slowtwitch graph has no indication of error on it, so it isn't possible to be sure what the numbers mean.

Sure you can adjust 23 mm tires to feel just like 28 mm tires by inflating them to about 0.5 bar higher than the 28s. Assuming that both tires are at pressures that are suitable for the particular ride-bike system weight. What I think you meant to say is that you can't get 23 mm tires low enough to feel as good as 28 mm tires do at their lowest proper inflation. That's right, but that's not what this discussion is about. If you shoot for best road feel, with any tire, you will sacrifice Crr. These articles are about minimizing Crr, not maximizing comfort. If you picked a bike-rider system weight and determined the minimum advisable tire pressure for that weight, I think you would find the Crrs of the differently inflated, different size tires remarkable similar. Not the comfort, but the Crr. The very low pressure 28 mm tire would feel better than the slightly higher pressure 25 mm tire and better yet than the still higher pressure 23 mm tire. But the Crrs would be very similar. And if you inflated the wider tires more to reap the Crr advantage, they would lost the comfort advantage. In fact all at the same pressure, the narrower tires would feel better through have a higher Crr.

You can't have it both ways. Compromise is the best approach.